"Ventral aspect of femal shore crab. Abd., Abdomen; mxp., third maxillipede." -Thomson, 1916

Female Shore Crab

"Ventral aspect of femal shore crab. Abd., Abdomen; mxp., third maxillipede." -Thomson, 1916

"Acorn-shell (Balanus tintinnabulum). T., tergum; CR., thoracic legs; R., outer shell in section; D., aperture of oviduct; F., mantle cavity; X., depressor muscle of tergum; AN., antennae; OV., ovary; G., depressor of scutum; H., oviduct; AM., adductor muscle of scuta; S., scutum." -Thomson, 1916

Acorn Shell

"Acorn-shell (Balanus tintinnabulum). T., tergum; CR., thoracic legs; R., outer shell in section; D.,…

"Nebalia. SH., Shell; A.1, first antennae; A.2, second antennae; TH., 8 thoracic limbs; Ab.4, Ab.6, fourth and sixth abdominal limbs." -Thomson, 1916

Nebalia

"Nebalia. SH., Shell; A.1, first antennae; A.2, second antennae; TH., 8 thoracic limbs; Ab.4, Ab.6,…

"Hermit-crab withdrawn from its shell. The anterior appendages are broken off. hd., Head; th., thorax; abd., abdomen." -Thomson, 1916

Hermit Crab

"Hermit-crab withdrawn from its shell. The anterior appendages are broken off. hd., Head; th., thorax;…

"Dissection of Peripatus. at., Antennae; or.p., oral papillae; c.g., cerebral ganglia; sl.d., duct of slime gland (sl.g.); s.o.8, eighth segmental organ or nephridium; v.c., ventral nerve connected by transverse commissures (co.) with its fellow; s.o.17, seventeenth nephridium; g.o., genital aperture; A., anus; p.d.c., posterior commissure; F.17, seventeenth appendage; a.g., last crural gland--that of the opposite side is marked v.g.; F.1, F.2 first and second legs; oe.co., osophageal nerve commisure; oe., oesophagus; ph., pharynx--the remainder of he gut is removed." -Thomson, 1916

Peripatus Dissection

"Dissection of Peripatus. at., Antennae; or.p., oral papillae; c.g., cerebral ganglia; sl.d., duct of…

"Ventral aspect of male cockroach with the wings extended. An imaginary median line has been inserted. A., antennae; E., eye; P.T., prothorax; W1, first pair of wings; W2, second pair of wings; C., cercus; St., style; Co., coxa; Tr., trochanter; F., femur; Ti., tibia; Ta., tarsus." -Thomson, 1916

Cockroach

"Ventral aspect of male cockroach with the wings extended. An imaginary median line has been inserted.…

"Leg of cockroach. c., Broad expanded coxa; tr., trochanter; f., femur; ti., tibia; ta., six-jointed tarsus with terminal claws and adhesive cushions." -Thomson, 1916

Cockroach Leg

"Leg of cockroach. c., Broad expanded coxa; tr., trochanter; f., femur; ti., tibia; ta., six-jointed…

"Transverse section of insect. h., Heart; g., gut; n., nerve-cord; st., stigma; tr., trachea; w., wing; f., femur of leg." -Thomson, 1916

Insect Section

"Transverse section of insect. h., Heart; g., gut; n., nerve-cord; st., stigma; tr., trachea; w., wing;…

"Head and mouth parts of bee. a., Antenna; m., mandible; g., labrum or epipharynx; mx.p., rudiment of maxillary palp; mx., lamina of maxilla; lp., labial palp; l., ligula; b., bouton at end. The paraglossae lie concealed between the basal portions of the labial palps and the ligula." -Thomson, 1916

Bee Head

"Head and mouth parts of bee. a., Antenna; m., mandible; g., labrum or epipharynx; mx.p., rudiment of…

"Mouth-parts of mosquito. a., Antennae; lxe., labrum and epipharynx; mn., mandibles; hp., hypopharynx; mx., first maxillae; li, labium; m.p., maxillary palps; cl., clypeus; cs., head scales." -Thomson, 1916

Mosquito Mouth Parts

"Mouth-parts of mosquito. a., Antennae; lxe., labrum and epipharynx; mn., mandibles; hp., hypopharynx;…

"A transverse section before the union of the amnion folds, and a longitudinal median section after the union of the fold. a., Anterior end of blastoderm; p.,. posterior end of blastoderm; a.f., in the left-hand figure, the beginning of the amnion fold; am., amnion; a.c., amniotic cavity; s., serosa; ec., ectoderm; ll., lower germinal layer; y., yolk. The amniotic cavity marks the future ventral region of the embryo, so that the yolk mass is dorsal." -Thomson, 1916

Insect Embryo

"A transverse section before the union of the amnion folds, and a longitudinal median section after…

"Acerentomon, a very primitive insect. H, Head; TH.1, TH.2, TH.3, terga of thoracic segments; 1, 2, 3, the thoracic legs; A.1, A.2, A.3, A.4, abdominal appendages; P.A., eighth abdominal tergum; G., genital aperture; AP.P., post-anal appendix." -Thomson, 1916

Acerentomon

"Acerentomon, a very primitive insect. H, Head; TH.1, TH.2, TH.3, terga of thoracic segments; 1, 2,…

"Vertical cross-section of a Trilobite (Calymene). i., Intestine; s., shield; L., endopodite; e., exopodite; b., epipodial parts." -Thomson, 1916

Trilobite

"Vertical cross-section of a Trilobite (Calymene). i., Intestine; s., shield; L., endopodite; e., exopodite;…

"Male of Nymphon. PR., Proboscis; CH., chelophores; P., pedipalps; E., eggs carried on ovigerous legs; A., rudimentary abdomen." -Thomson, 1916

Nymphon Sea Spider

"Male of Nymphon. PR., Proboscis; CH., chelophores; P., pedipalps; E., eggs carried on ovigerous legs;…

"Ideal mollusc. m., Mouth; g.c., cerebral ganglia; c., edges of mantle skirt; z.g., duct of right lobe of digestive gland; s., pericardial cavity; f., edges of shell-sac; v., ventricle of heart; u., nephridium; an., anus; n., posterior part of the foot; l., opening of nephridium; k., genital aperture; g.ab., abdominal ganglion on visceral loop; g.v., visceral ganglion; z.l., left lobe of digestive gland; p., foot; g.pe., pedal ganglion; g.pl. pleural ganglion." -Thomson, 1916

Mollusc Parts

"Ideal mollusc. m., Mouth; g.c., cerebral ganglia; c., edges of mantle skirt; z.g., duct of right lobe…

"Roman snail (Helix pomatia). Note shell covering visceral hump; p.ap., pulmonary aperture (including anus and opening of ureter); f., the foot; g.ap., genital aperture; m., mouth; e., eye on long horn; s.h., one of short horns." -Thomson, 1916

Roman Snail

"Roman snail (Helix pomatia). Note shell covering visceral hump; p.ap., pulmonary aperture (including…

"Vertical section of the shell of a species of Helix. M., Mouth of shell; A., apex; C., columella." -Thomson, 1916

Shell

"Vertical section of the shell of a species of Helix. M., Mouth of shell; A., apex; C., columella."…

"Dissection of snail. T., Short horn; TT., long horn with eye; N., cerebral ganglia; S.G., salivary glands on the crop; F., foot; M., columellar muscle; V.C., visceral coil; O.T., ovotestis; V., ventricle of heart; R. rectum; U., ureter; B.V., blood vessels returning to the auricle from the mantle; A., pulmonary aperture; MA., edge of the mantle." -Thomson, 1916

Dissection

"Dissection of snail. T., Short horn; TT., long horn with eye; N., cerebral ganglia; S.G., salivary…

"The fresh-water mussel...the bivalve in motion in the mud with protruded foot (F.); nonte inhaland and exhalant apertures...u., the umbo." -Thomson, 1916

Freshwater Mussel

"The fresh-water mussel...the bivalve in motion in the mud with protruded foot (F.); nonte inhaland…

"The fresh-water mussel...the inside of the shell (left valve)...u., The umbo; L., the ligament; c.t., lateral teeth; a.a., anterior adductor mark; a.r., mark of protractor of the foot; p.l., pallial line; p.a., posterior adductor mark; p.r., mark of posterior retractor of the foot; A., anterior (the blunter end); P., posterior." -Thomson, 1916

Freshwater Mussel

"The fresh-water mussel...the inside of the shell (left valve)...u., The umbo; L., the ligament; c.t.,…

"The fresh-water mussel...the outside of the shell (right valve)...u., The umbo; L., the ligament; l.g., a line of growth; A., anterior (the blunter end); P., posterior; V., ventral." -Thomson, 1916

Freshwater Mussel

"The fresh-water mussel...the outside of the shell (right valve)...u., The umbo; L., the ligament; l.g.,…

"Diagram of the structure of Sepia. a., Eight short arms around mouth; l.a., one of the two long arms; b., beak of the mouth; c.g., cerebral ganglia, with commissures to the others; E., eye; g., gullet; d.g., digestive gland (the "salivary glands" are not represented); st., stomach; a., anus; sh., shell-sac with sepiostaire; k., kidney; R., reproductive organ; br.h., branchial heart; g., a gill; i.b., ink-bag; m.c., mantle cavity; f., funnel." -Thomson, 1916

Cuttlefish Structure

"Diagram of the structure of Sepia. a., Eight short arms around mouth; l.a., one of the two long arms;…

"Diagram of circulatory and excretory systems in a Decapod-like Sepia. 1, Gill; 2, renal sac; 3, afferent branchial vessel; 4, branchial heart; 5, abdominal vein; 6, heart; 7, viscero-pericardial sac (body cavity); 8, genital organ; 9, posterior aorta; 10, "auricle"; 11, glandular appendix of branchial heart; 12, renal appendices of branchial vein; 13, external aperure of kidney; 14, vena cava; 15, anterior aorta; 16, bifurcation of vena cava; 17, reno-pericardial aperture." -Thomson, 1916

Cuttlefish Circulatory and Excretory Systems

"Diagram of circulatory and excretory systems in a Decapod-like Sepia. 1, Gill; 2, renal sac; 3, afferent…

"Bunch of Sepia eggs attached to plant." -Thomson, 1916

Cuttlefish Eggs

"Bunch of Sepia eggs attached to plant." -Thomson, 1916

"'Nurse' of Doliolum mulleri. I., Inhalant, E., exhalant aperture; C., ciliated band round pharynx (P.); En., endostyle; O., "otocyst"; N., nerve-ganglion; H., heart; (E., oesophageal opening; D., stomach; A., anus; Cl., cloaca; DO., dorsal organ; M., muscle bands." -Thomson, 1916

Doliolum Mulleri

"'Nurse' of Doliolum mulleri. I., Inhalant, E., exhalant aperture; C., ciliated band round pharynx (P.);…

"Sexual individual of Doliolum mulleri. G., gonads; B., gill-slits; I., Inhalant, E., exhalant aperture; C., ciliated band round pharynx (P.); En., endostyle; O., "otocyst"; N., nerve-ganglion; H., heart; (E., oesophageal opening; D., stomach; A., anus; Cl., cloaca; DO., dorsal organ; M., muscle bands." -Thomson, 1916

Doliolum Mulleri

"Sexual individual of Doliolum mulleri. G., gonads; B., gill-slits; I., Inhalant, E., exhalant aperture;…

"Diagram of Salpa africana. o.a., Oral aperture; d.t., dorsal tubercle; te., tentacle; g., ganglion; m., muscle bands; atr., atrium; b.v., blood-vessel; an., anus; a.a., exhalant aperture; v.n., visceral nucleus; h., heart st., stolon; d.l., dorsal lamina; E., endostyle; s.n.g., sub-neural gland; ph., pharynx; p.p.b., peri-pharyngeal band." -Thomson, 1916

Salpa Africana

"Diagram of Salpa africana. o.a., Oral aperture; d.t., dorsal tubercle; te., tentacle; g., ganglion;…

"Lateral view of Amphioxus. The notochord runs from tip to tip. t., Tentacular cirri; G., reproductive organs; a.p., atriopore; a., position of anus; 40 and 62, indicate number of myotomes." -Thomson, 1916

Lancelet

"Lateral view of Amphioxus. The notochord runs from tip to tip. t., Tentacular cirri; G., reproductive…

"Partial section of a Vertebrate brain (diagrammatic). OLF., Olfactory lobe; CH., cerebral hemispheres; C., wall of cerebrum cut to show ventricle, behind this the figure is that of a median section; PA., parietal organ arising from thalamencephalon; Pl., pineal organ; INF., infundibulum descending from thalamencephalon; H., hypophysis; OL., optic lobes; CB., cerebellum; CPL., choroid plexus on roof of fourth ventricle; MO., floor of the medulla oblongata; CC., central canal of spinal cord." -Thomson, 1916

Vertebrate Brain

"Partial section of a Vertebrate brain (diagrammatic). OLF., Olfactory lobe; CH., cerebral hemispheres;…

"Diagrammatic section of spinal cord. p.f., Posterior fissure; p.c., posterior column of white matter; d.p.s., dorsal, posterior, sensory or afferent root; g., ganglion; v.a.m., ventral, anterior, motor or efferent root; c.n., compound spinal nerve with branches; s.g., sympathetic ganglion; a.c., anterior column--the anterior fissure is exaggerated; g.c., ganglion cells; g.m., grey matter; w.m., white matter." -Thomson, 1916

Vertebrate Spinal Cord

"Diagrammatic section of spinal cord. p.f., Posterior fissure; p.c., posterior column of white matter;…

"Diagram showing the ear and related parts in a young cat. P., Pinna; Sq., squamosal: E.A.M., external auditory meatus; T., tympanum; M., malleus; I., incus; St., stapes abutting onforamen ovale; B., bulla of tympanic bone; Se., a septum in the bulla; E.T., eustachian tube leading from the tymmpanic cavity to the back of the mouth; B.O., basi-occipital; C., cochlea; S., sacculus; U., utriculus; D.E., ductus endolymphaticus; N., auditory nerve; S.C., semi-circular canal; PE., periotic bone." -Thomson, 1916

Cat Ear

"Diagram showing the ear and related parts in a young cat. P., Pinna; Sq., squamosal: E.A.M., external…

"Diagram of the eye. C., Cornea; a.h., aqueous humour; c.b., ciliary body; l., lens; I., iris; Sc., sclerotic; Ch., choroid; R., retina; v.h., vitreous humour; y.sp., yellow spot; n., optic nerve." -Thomson, 1916

Eye

"Diagram of the eye. C., Cornea; a.h., aqueous humour; c.b., ciliary body; l., lens; I., iris; Sc.,…

"Section through a young newt. c.t., Connective tissue; E., epidermis; D., dermis; S.C., spinal cord; M., muscle; N., notochord; Sh., mesodermic sheath of notochord; K., kidney; l., lung; S., spleen; ST., stomach; Pe., peritoneum; L., liver; d., duct of the pancreas (P); G.B., gall-bladder; V., dorsal aorta." -Thomson, 1916

Newt Anatomy

"Section through a young newt. c.t., Connective tissue; E., epidermis; D., dermis; S.C., spinal cord;…

"Median longitudinal section of anterior region of Myxine. B., Barbule; N., nasal aperture; NT., nasal tube with rings of cartilage; NC., nasal capsule; BR., brain; SC., spinal cord; N., notochord; G., gut; T., cartilage of "tongue"; MU., muscle; NTT., posterior part of nasal sac; TP., a tooth plate; MT., median tooth on roof of mouth (M.)." -Thomson, 1916

Hagfish Anterior

"Median longitudinal section of anterior region of Myxine. B., Barbule; N., nasal aperture; NT., nasal…

"Respiratory system of hag, from ventral surface. b., Barbules; m., mouth opening on ventral surface; g., gullet; g.p'., first gill-pouch, cut open to show internal lamellae; g.p.6, sixth gill-pouch; v., ventricle of heart; ao., aorta; a., common exhalant aperture." -Thomson, 1916

Hagfish Respiratory System

"Respiratory system of hag, from ventral surface. b., Barbules; m., mouth opening on ventral surface;…

"Bdellostoma stouti (Californian hag), enveloped in sheath of mucus. b., barbules e., eyes m. mucus; eg., eggs." -Thomson, 1916

Californian Hagfish

"Bdellostoma stouti (Californian hag), enveloped in sheath of mucus. b., barbules e., eyes m. mucus;…

"The lamprey (Petromyzon marinus). I. Then entire animal; note the seven gill-slits of which the first is marked g.s., the nostril n., and the unpaired median fins. II. Ventral aspect of the head; u.t., upper teeth; l.t., lower teeth; p., the piston in the mouth. III. Upper surface of the head; n., the nostril with the pineal groove behind it; e., the eye." -Thomson, 1916

Sea Lamprey

"The lamprey (Petromyzon marinus). I. Then entire animal; note the seven gill-slits of which the first…

"Under surface of skull and arches of skate. l.1, First labial cartilage; R., rostrum; tr., trabecular region; n.c., nasal capsule; a.o., antorbital cartilage; p.pt.q., palato-pterygo-quadrae; M.c., Meckel's cartilage; h.m., hyo-mandibular; h.br.1-5, hypobranchials; c.br.5, fifth ceratobranchial; c.h., cerato-hyal; l.2-4, labial cartilages." -Thomson, 1916

Skate Skull

"Under surface of skull and arches of skate. l.1, First labial cartilage; R., rostrum; tr., trabecular…

"Side view of skate's skull. l1., First labial cartilage; n.c., nasal capsule; a.o., antorbital; p.pt.q., palato-pterygo-quadrate; M.c., Meckel's cartilage; h.m., hyo-mandibular; e.h., epi-hyal; c.h., cerato-hyal; h.h., hypo-hyal; h.br.1-5, hypobranchials; c.br., ceratobranchial; e.br., epibranchial; p.br.1., first prebranchial; i.h., inter-hyal; m.pt., meta-pterygoid; 2, 5, 7, foramina of exit of the corresponding nerves." -Thomson, 1916

Skate Skull

"Side view of skate's skull. l1., First labial cartilage; n.c., nasal capsule; a.o., antorbital; p.pt.q.,…

Skeleton of skate. nc, nasal capsules; pq, palato-pterygo-quadrate cartilage; M, Meckel's cartilage; hm, hyo-mandibular; h.br., fifth hypobranchial; v.pl., vertebral plate; st, sensory tubes; sc, scapular region; c, coracoid region; p.pt., anterior basal cartilage or pro-pterygium; m.pt., meso pterygium; mt.pt., meta-pterygium; pu., pubic bar; st, stomach; sv, spiral valve of intestine. -Thomson, 1916

Skate Skeleton

Skeleton of skate. nc, nasal capsules; pq, palato-pterygo-quadrate cartilage; M, Meckel's cartilage;…

"Dissection of nerves of skate. CH., Cerebral hemispheres; O.TH., optic thalami; OL., optic lobes; M., medulla; 4v., posterior part of cerebellum, covering fourth ventricle; OB., olfactory bulb; OC., olfactory capsule; SO., superior oblique muscle; E., eye; SR., superior rectus; ER., external rectus; SO.VII., superficial ophthalmic branch of VII.; SO.V., superficial ophthalmic branch of V.; OP., ophthalmicus profundus; A.C., auditory capsule; B.Pl., brachial plexus; R.F., recurrent facial; C.T., chorda tympani; F.P., facial proper; Hy., hyoidean; Hyomn., hyomandibular; E.M., external mandibular; M.M., mandibular muscle; Sp., spiracle; P.sp., prespiracular; Pl., palatine; O.B., outer buccal; Mn., mandibular; Mx., maxillary; I.B., inner buccal; L., lateral branch of X.; Py., pyloric branch; C., cardiac branch." -Thomson, 1916

Skate Nerves

"Dissection of nerves of skate. CH., Cerebral hemispheres; O.TH., optic thalami; OL., optic lobes; M.,…

"Heart and adjacent vessels of skate. v., Ventricle; c.a., conus arteriosus; p.i., posterior innominate; v.a., ventral aorta; a.i., anterior innominate; Th., thyroid; m., mouth; a., auricle; s.v., sinus venosus; s.c., precaval sinus or sinus of Cuvier; h.s., hepatic sinus; j., jugular; br., brachials; cd., cardinal; epg., epigastric." -Thomson, 1916

Skate Heart

"Heart and adjacent vessels of skate. v., Ventricle; c.a., conus arteriosus; p.i., posterior innominate;…

"The haddock. n.a., Nasal apertures (double on each side); d.f.1, d.f.2, d.f.3, dorsal unpaired fins; c.f., the caudal fin of the homocercal tail. b., Barbule; op., operculum covering the four gills; br.m., continuation of the gill-cover forming the branchiostegal membrane; pv.f., pelvic fin (=hind-limb)--note its jugular position in front of p.f., the pectoral fin (=fore-limb)." -Thomson, 1916

Haddock

"The haddock. n.a., Nasal apertures (double on each side); d.f.1, d.f.2, d.f.3, dorsal unpaired fins;…

"External characters of a Teleostean--a carp (Cyprinus carpio). R., Dorsal unpaired fin; S., homocercal caudal fin; A., anal fin; B., B., pectoral and pelvic paired fins. Note also the lateral line and barbule." -Thomson, 1916

Carp

"External characters of a Teleostean--a carp (Cyprinus carpio). R., Dorsal unpaired fin; S., homocercal…

"Section of a Teleostean gill. G.F., Gill-filament; A., artery (venous blood); V., vein (pure blood); G.A., gill-arch." -Thomson, 1916

Teleostean Gill

"Section of a Teleostean gill. G.F., Gill-filament; A., artery (venous blood); V., vein (pure blood);…

"Diagram of Teleostean circulation. A., auricle; V., ventricle; v.a., ventral aorta; a.br., afferent branchials; e.br., efferent branchials; c.c., cephalic circle; e., carotids; A.c.v., anterior cardinal veins; P.C.V., posterior cardinal veins; d.c., ductuss Cuvieri; d.a., dorsal aortaa; c.v., caudal vein; c.a., caudal artery; K., kidney." -Thomson, 1916

Teleostean Circulation

"Diagram of Teleostean circulation. A., auricle; V., ventricle; v.a., ventral aorta; a.br., afferent…

"Young skate. The yolk-sac has been cut off, the yolk-stalk is left. m., Mouth; ol.o., nostril, e.g. "external gills", a., cloaca; c., claspers." -Thomson, 1916

Young Skate

"Young skate. The yolk-sac has been cut off, the yolk-stalk is left. m., Mouth; ol.o., nostril, e.g.…

"Lateral view of dogfish (Scyllium catulus). Note ventral mouth with naso-buccal groove, heterocercal tail, and unpaired fins. gs., Gill-slits; pc., pectoral fins; pv., pelvic fins." -Thomson, 1916

Dogfish

"Lateral view of dogfish (Scyllium catulus). Note ventral mouth with naso-buccal groove, heterocercal…

"Outline of Acanthodes sulcatus. p., Pectoral fins; v., pelvis; a., anal; d., dorsal." -Thomson, 1916

Acanthodes Sulcatus

"Outline of Acanthodes sulcatus. p., Pectoral fins; v., pelvis; a., anal; d., dorsal." -Thomson, 1916

"Larva of Polypterus. e.g., Large external gill of the hyoid arch; Pc., pectoral fins; Pv., pelvic fins. The larva is drawn in a very characteristic attitude." -Thomson, 1916

Polypterus

"Larva of Polypterus. e.g., Large external gill of the hyoid arch; Pc., pectoral fins; Pv., pelvic fins.…

"Lepidosiren showing (Pc.f.) pectoral fin and the tufted pelvic fin (Pv.f.) of the mature male." -Thomson, 1916

South American Lungfish

"Lepidosiren showing (Pc.f.) pectoral fin and the tufted pelvic fin (Pv.f.) of the mature male." -Thomson,…

"Skeleton of Ceratodus fin. a., Central axis; r., radials; h., basal piece." -Thomson, 1916

Queensland Lungfish Fin

"Skeleton of Ceratodus fin. a., Central axis; r., radials; h., basal piece." -Thomson, 1916

"Head region of Protopterus. sn.t., Sensory tubes; l.l., lateral line; e.br., external gills; pc.l., pectoral fin; op., operculum." -Thomson, 1916

African Lungfish Head

"Head region of Protopterus. sn.t., Sensory tubes; l.l., lateral line; e.br., external gills; pc.l.,…

"Larva of Protopterus. e.g., external gills; Pc., pectoral fin; Pv., pelvic fin." -Thomson, 1916

African Lungfish Larva

"Larva of Protopterus. e.g., external gills; Pc., pectoral fin; Pv., pelvic fin." -Thomson, 1916

"Skull of frog. Upper surface-- Pmx., premaxilla; N., nasal; M., maxilla; Sq., squamosal; Q.j., quadrato-jugal; e.o., ex-occipitals; P.f., parieto-frontals; Sph.E., sphenethmoid; P.O., pro-otic." -Thomson, 1916

Upper Surface of Frog Skull

"Skull of frog. Upper surface-- Pmx., premaxilla; N., nasal; M., maxilla; Sq., squamosal; Q.j., quadrato-jugal;…

"Skull of frog. Lower surface-- Pmx., premaxilla; M., maxilla; Q.j., quadrato-jugal; Q., quadrate; Pt., pterygoid; Ps., parasphenoid; P.O., pro-otic; Sp.E., sphenethmoid; Pl., palatine; V., vomer; c., columella." -Thomson, 1916

Lower Surface of Frog Skull

"Skull of frog. Lower surface-- Pmx., premaxilla; M., maxilla; Q.j., quadrato-jugal; Q., quadrate; Pt.,…

"Skeleton of frog. The half of the pectoral girdle, and fore- and hind-limb of the right side are not shown. pmx., premaxilla; m.x., maxilla; n., nasal; sph., sphenethmoid; p.f., parieto-frontal; P.O., pro-otic; pt., pterygoid; q.j., quadrato-jugal; sq., squamosal; Q., quadrate; c., columella auris; A., atlas; t.p., transverse process; S.V., sacral vertebra; U., urostyle; S.sc., supra scapula; H., humerus; R.U., radio ulna; Cp., carpals; Mc., metacarpals; Il., ilium; Is., ischium; F., femur; T.F., tibio-fibula; Ca., calcaneum; As., astragalus; C., calcar; Mt., metatarsals." -Thomson, 1916

Frog Skeleton

"Skeleton of frog. The half of the pectoral girdle, and fore- and hind-limb of the right side are not…

"Pectoral girdle of Rana esculenta. The cartilaginous parts are dotted. Ep., Episternum; om., omosternum; Ep.c., Epicoracoids; st., sternum; x., xiphisternum; cl., clavicle with underlying precoracoid cartilage; co., coracoid; Sc., scapula; S.sc., supra-scapula; Gl., glenoid cavity for humerus." -Thomson, 1916

Frog Pectoral Girdle

"Pectoral girdle of Rana esculenta. The cartilaginous parts are dotted. Ep., Episternum; om., omosternum;…

"Nervous system of frog. 1-10, The cranial nerves; oc., eyes; crb., in front of optic chiasma; to., optic tract; sym., sympathetic system; msp., spinal cord; sp., spinal nerves." -Thomson, 1916

Frog Nervous System

"Nervous system of frog. 1-10, The cranial nerves; oc., eyes; crb., in front of optic chiasma; to.,…

"Longitudinal vertical section of frog embryo, shortly before closure of blastopore. FB., fore-brain; EC., ectoderm; N., notochord; SC., canal of spinal cord; NE., nerenteric canal; B., blastopore; M., mesoderm; P., beginning of pituitary invagination." -Thomson, 1916

Frog Embryo

"Longitudinal vertical section of frog embryo, shortly before closure of blastopore. FB., fore-brain;…