"Cross-section of Arenicola. E., Epidermis; c.m., circular muscles; l.m., longitudinal muscles; b.c., body cavity; gl., gill; s., setae; n.p., nephridial pore; a.br., afferent branchial; e.br., efferent branchial; n., ventral nerve-cord, with blood vessels above; d.v., dorsal vessel; l.v., lateral vessel; s.i.v., sub-intestinal vessels; v.v., ventral vessel; g., gut." -Thomson, 1916

Arenicola

"Cross-section of Arenicola. E., Epidermis; c.m., circular muscles; l.m., longitudinal muscles; b.c.,…

"Daphnia. E., Eye; A.2, second antenna; A.1, first antenna; dg., digestive caeca; s.g., shell gland; go., gonad; h., heart in pericardium; o., ovum; B.p., brood-pouch; sp., spine; f., furca; s., setae; Ab., rudimentary abdomen; t., caudal fork; g., gut; 1-5, thoracic limbs." -Thomson, 1916

Daphnia

"Daphnia. E., Eye; A.2, second antenna; A.1, first antenna; dg., digestive caeca; s.g., shell gland;…

"Anterior region of earthworm. Note the eight setae (s.) on each segment. R.S., Spots between 9-10, 10-11, indicate openings of receptacula seminis; Ovd., openings of oviducts on segment 14/ vd., openings of vasa deferentia on segment 13." -Thomson, 1916

Earthworm

"Anterior region of earthworm. Note the eight setae (s.) on each segment. R.S., Spots between 9-10,…

"Reproductive organs of earthworm. N., Nerve cord; T., anterior testes; S., sacs of setae; R.S., receptacula seminis; s.f., seminal funnels; v.d., vas deferens; ovd., oviduct; ov., ovary; sv., seminal vesicles cut open; VIII.-XV., segmens" -Thomson, 1916

Earthworm Reproductive Organs

"Reproductive organs of earthworm. N., Nerve cord; T., anterior testes; S., sacs of setae; R.S., receptacula…

"Lumbricus agricola. A, entire specimen, lateral view; B, ventral view of anterior portion of the body, magnified. 1, 15, 33, first, fifteenth, and thirty-third segments. The black dots represent the setae." -Parker, 1900

Lumbricus Agricola

"Lumbricus agricola. A, entire specimen, lateral view; B, ventral view of anterior portion of the body,…

"Triarthrus Becki, Green. Dorsal view of second thoracic leg with and without setae. en, Inner ramus; ex, Outer ramus." — The Encyclopedia Britannica, 1910

Triarthrus

"Triarthrus Becki, Green. Dorsal view of second thoracic leg with and without setae. en, Inner ramus;…