An illustration of a sectional view of a Acanthobdella, a member of the annelid family. "c, Coelom; c.ch, Coelomic epithelium (yellow cells); cg, glandular cells; cl, Muscle cells of lateral line; cp, Pigment cells; ep, Ectoderm; g, Nerve cord; m, Intestine; mc, Circular muscle; ml, Longitudinal muscle; vd, Dorsal vessel; ww, Ventral vessel." (Britannic, 1910)

Sectional View of Acanthobdella

An illustration of a sectional view of a Acanthobdella, a member of the annelid family. "c, Coelom;…

Amphitrite ornata.

Amphitrite Ornata

Amphitrite ornata.

"The <em>Leodice antennata</em> has the organs of locomotion attached to each segment; they are usually in the form of movable spines, and are used as oars." &mdash; Goodrich, 1859

Leodice antennata

"The Leodice antennata has the organs of locomotion attached to each segment; they are usually…

"Army-worm (Leucania unipuncta), about natural size. a, male moth; b, abdomen of female; c, eye; d, pupa; e, caterpillar."-Whitney, 1902

Army Worm

"Army-worm (Leucania unipuncta), about natural size. a, male moth; b, abdomen of female; c, eye; d,…

"The Army Worm (Leucania unipuncta). A, caterpillar; B, adult moth." &mdash; Galloway

Army Worm

"The Army Worm (Leucania unipuncta). A, caterpillar; B, adult moth." — Galloway

The larva stage of the longhorn beetle (Saperda candida).

Longhorn Beetle Larva

The larva stage of the longhorn beetle (Saperda candida).

Illustration of a female green spoonworm. A, Proboscis cut short; B, bristle passing though the mouth into the pharynx; C, coiled intestine; D, anal tufts or vesicles; E, ventral nerve cord; F, ovary borne on ventral vessel running parallel with e; G, position of anus; H,, position of external opening of; I, nephridium --- the line points towards, but does not reach, the internal opening.

Bonellia Viridis (Female)

Illustration of a female green spoonworm. A, Proboscis cut short; B, bristle passing though the mouth…

Illustration of a male green spoonworm. A, Bonellia viridis; B, mouth; C, ventral hooks; and d, anus. The Green Spoonworm (Bonellia viridis) is a marine worm (phylum Echiura) noted for displaying exceptional sexual dimorphism and for the biocidal properties of a pigment in its skin

Bonellia Viridis (Male)

Illustration of a male green spoonworm. A, Bonellia viridis; B, mouth; C, ventral hooks; and d, anus.…

Illustration of a male green spoonworm. A, Generative pore with spermatozoa; B, Anterior blind end of intestine attached to the parenchymatous tissue by muscular strands; C, Green wandering cells containing chlorophyll; D, Parenchymatous connective tissue; Epidermis, I, Intestine; J, Vas deferens; L, Internal opening of vas deferens; M, The left anal vesicle; and M, Spermatozoa in the body-cavity.

Bonellia Viridis (Male)

Illustration of a male green spoonworm. A, Generative pore with spermatozoa; B, Anterior blind end of…

"Cabage butterfly (female), parent of the cabbage-worm." &mdash; Baily, 1898

Cabbage Butterfly

"Cabage butterfly (female), parent of the cabbage-worm." — Baily, 1898

A fleshy caterpillar.

Milkweed Butterfly Larva

A fleshy caterpillar.

A caterpillar of the Clisiocampa genus.

Caterpillar

A caterpillar of the Clisiocampa genus.

A cabbage plusia caterpillar crawling on a leaf.

Caterpillar

A cabbage plusia caterpillar crawling on a leaf.

The caterpillar stage of the double-toothed prominent (Nerice bidentata) showing its serrated back.

Double-Toothed Prominent Caterpillar

The caterpillar stage of the double-toothed prominent (Nerice bidentata) showing its serrated back.

A large caterpillar with long, skinny horns. Usually a beautiful olive and crimson color.

Royal Horned Caterpillar

A large caterpillar with long, skinny horns. Usually a beautiful olive and crimson color.

A caterpillar with a saddle type pattern on its back.

Saddleback Caterpillar

A caterpillar with a saddle type pattern on its back.

"A Centipede is a worm having a long slender, depressed body, protected by coriaceous plates, 21 pairs of legs, distinct eyes, 4 on each side, and antenn&aelig; with 17 joints. The name is, however, popularly extended to species of nearly allied genera. Centipedes run nimbly, feed on insects, and pursue them into their lurking-places."&mdash;(Charles Leonard-Stuart, 1911)

Giant Centipede

"A Centipede is a worm having a long slender, depressed body, protected by coriaceous plates, 21 pairs…

Chaetognatha is a phylum of predatory marine worms that are a major component of plankton worldwide. About 20% of the known species are benthic and can attach to algae or rocks. They are found in all marine waters from surface tropical waters and shallow tide pools to the deep sea and polar regions. Most chaetognaths are transparent and are torpedo shaped. Some deep-sea species are orange. They range in size from 2 mm to 12 cm. The common term for the phylum is Arrow Worms. There are more than 120 modern species assigned to over 20 genera. Despite the limited diversity of species, the number of individuals is staggering.

Chaetognatha

Chaetognatha is a phylum of predatory marine worms that are a major component of plankton worldwide.…

Anterior part of the circulatory system of an annelid. The arrows indicate the direction of the flow. H, heart-like enlargement of the commissural vessel.

Circulatory System of an Annelid

Anterior part of the circulatory system of an annelid. The arrows indicate the direction of the flow.…

An adult cotton-boll worm, in the form of a moth.

Cotton Boll Worm, Adult

An adult cotton-boll worm, in the form of a moth.

"W-Marked Cutworm and Greasy Cutworm Moth."-Whitney, 1902

Cutworm

"W-Marked Cutworm and Greasy Cutworm Moth."-Whitney, 1902

A cutworm larva.

Cutworm

A cutworm larva.

The caterpillar form of the cottonwood moth.

Cottonwood Dagger

The caterpillar form of the cottonwood moth.

A caterpillar that feeds mostly on the cottonwood leaves.

Smeared Dagger

A caterpillar that feeds mostly on the cottonwood leaves.

The larva is a gooseberry fruit worm.

Dakruma

The larva is a gooseberry fruit worm.

"Demoscolecida, a group of minute marine worm-like creatures. The body tapers towards each end and is marked by a number f well define ridges." -Britannica, 1910

Demoscolecida

"Demoscolecida, a group of minute marine worm-like creatures. The body tapers towards each end and is…

"The bodies of these animals are of a cylindrical form, somewhat pointed at the anterior extremity, and usually a little flattened at the tail. The skin is tough, and divided into numerous segments by transverse wrinkles, and the organs of motion are reduced to the form of a double row of bristles, running down the lower surface of the body." &mdash; Goodrich, 1859

Earth-worms

"The bodies of these animals are of a cylindrical form, somewhat pointed at the anterior extremity,…

Side view of internal structures of earthworm.

Earthworm

Side view of internal structures of earthworm.

Dorsal view of internal structures of earthworm after cutting through the dorsal wall lengthwise and turning it outward.

Earthworm

Dorsal view of internal structures of earthworm after cutting through the dorsal wall lengthwise and…

Cross section of earthworm.

Earthworm

Cross section of earthworm.

"Diagrams of various earthworms to illustrate external characters. A, B, C, anterior segments from the ventral surface; D, hinder end of the body of Urochaeta." (Britannica, 1910)

Earthworm

"Diagrams of various earthworms to illustrate external characters. A, B, C, anterior segments from the…

The earthworms are also known as megadriles, in the families Tubificidae, Lumbriculidae, and Enchytraeidae, among others. The basic body plan is a tube, the digestive system, within a tube, the muscular slimy, moist outer body. The body is annular, formed of segments that are most specialized in the anterior and have a simple circulatory system. They have two main blood vessels that extend through the length of their body: a ventral blood vessel which leads the blood to the posterior end, and a dorsal blood vessel which leads to the anterior end. The dorsal vessel is contractile and pumps blood forward, where it is pumped into the ventral vessel by a series of "hearts" (aortic arches) which vary in number in the different taxa.

Earthworm

The earthworms are also known as megadriles, in the families Tubificidae, Lumbriculidae, and Enchytraeidae,…

The earthworms are also known as megadriles, in the families Tubificidae, Lumbriculidae, and Enchytraeidae. Earthworms have a pair of kidneys to every segment, each consisting of a coiled tube wrapped in a mass of small blood vessels, and at its inner end communicating with the body cavity by means of a funnel-shaped opening. Here is a diagram of an earthworm kidney., showing (b) blood vessel, (f) funnel opening into body cavity, (o) outer opening, (s)septum, (w) body wall

Earthworm Anatomy

The earthworms are also known as megadriles, in the families Tubificidae, Lumbriculidae, and Enchytraeidae.…

An illustration of the various types of earthworm setae. Seta (plural: setae) is a biological term derived from the Latin word for "bristle". It refers to a number of different bristle- or hair-like structures on living organisms. "A, penial seta of Perichaeta ceylonica; b, extremity of penial seta of Acanthodrilus; c, Seta of Urochaeta; d, Seta of Lumbricus; e, Seta of Criodrilus; f, g, Setae of Bohemilla comata; h, i, j, Setae of Psammoryctes barbatus." (Britannica, 1910)

Setae of Earthworm

An illustration of the various types of earthworm setae. Seta (plural: setae) is a biological term derived…

Caterpillar eggs on a branch.

Caterpillar Eggs

Caterpillar eggs on a branch.

A cross sectional view of the Dicyemennea Eledones, a parasite, found in Eledone Moschata, or musky octopus.

Dicyemennea Eledones Worm Found in Kidney of Octopus

A cross sectional view of the Dicyemennea Eledones, a parasite, found in Eledone Moschata, or musky…

Hook baited with worm.

Fishing

Hook baited with worm.

Hook baited with worm.

Fishing

Hook baited with worm.

Hook baited with worm.

Fishing

Hook baited with worm.

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds, or along the seacoast while a variety of other species are parasitic. The free forms are usually small, barely reaching a length greater than five or seven cetimeters (2 to 3 inches). Some of the parasitic species attain the great length of six to thirteen meters (20 to 40 feet). This is a fresh water flatworm.

Flatworm

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds,…

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds, or along the seacoast while a variety of other species are parasitic. The free forms are usually small, barely reaching a length greater than five or seven cetimeters (2 to 3 inches). Some of the parasitic species attain the great length of six to thirteen meters (20 to 40 feet). This is a marine flatworm.

Flatworm

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds,…

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds, or along the seacoast while a variety of other species are parasitic. The free forms are usually small, barely reaching a length greater than five or seven cetimeters (2 to 3 inches). Some of the parasitic species attain the great length of six to thirteen meters (20 to 40 feet). This is a fresh water flatworm. This is an anatomy of freshwater flatworm (Planaria), showing the excretory system, with flame-cell. The alimentary canal is stippled.

Flatworm

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds,…

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds, or along the seacoast while a variety of other species are parasitic. The free forms are usually small, barely reaching a length greater than five or seven cetimeters (2 to 3 inches). Some of the parasitic species attain the great length of six to thirteen meters (20 to 40 feet). This shows the nervous system of the flatworm.

Flatworm

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds,…

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds, or along the seacoast while a variety of other species are parasitic. The free forms are usually small, barely reaching a length greater than five or seven cetimeters (2 to 3 inches). Some of the parasitic species attain the great length of six to thirteen meters (20 to 40 feet). This is the flame-cell of the flatworm showing the flagellum (f), the nucleus (n), space among the organs of the body, (v) waste material.

Flatworm

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds,…

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds, or along the seacoast while a variety of other species are parasitic. Some of the parasitic species attain the great length of six to thirteen meters (20 to 40 feet). This parasitic flatworm diagram shows the (m) mouth, the (o) opening of the reproductive system, and (s) sucker and spines for attachment. The digestive system is stippled and the nervous system is black.

Flatworm

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds,…

An illustration of an apple-worm fly.

Apple-worm Fly

An illustration of an apple-worm fly.

Gepyrea is a name formerly given to a class of worms which included three families: (1) Priapulidae; (2) Sipunculidae; (3) Echiuridae. The three families have little in common, and the class Gephyrea has ceased to exist in strict systematic zoology. This illustration shows and example from each of the three families: (1) Priapulus caudatus; (2) Sipunculus nudus; (3) Echiurus Pallasi.

Gephyrea

Gepyrea is a name formerly given to a class of worms which included three families: (1) Priapulidae;…

Illustration showing different rhompalura gairdii flat worms. The left and the right worms are the female, and the middle is the full grown male.

Rhopalura Gairdii Flat Worm

Illustration showing different rhompalura gairdii flat worms. The left and the right worms are the female,…

"The female is chiefly luminous. It is a flat, grayish-brown creature, rather more than half an inch long, and quite destitute of wings. The male, on the contrary, is active, and flies well; and the luminosity of the emale appears to be intended to attract her volatile companion." &mdash; Goodrich, 1859

Glowworm

"The female is chiefly luminous. It is a flat, grayish-brown creature, rather more than half an inch…

Echinoderes dujardini is a worm-like creature in the Kinorhyncha phylum of mud dragons.

Kinorhynch

Echinoderes dujardini is a worm-like creature in the Kinorhyncha phylum of mud dragons.

A larva of a ladybird.

Ladybird

A larva of a ladybird.

Larva feeding on a grape leaf.

Larva

Larva feeding on a grape leaf.

"Errantia means <em>wandering</em>, and is applied to numerous species, of which the Lob-worm or Lug-worm, <em>Arenicola piscatorum</em>, is a common example. This animal, much used by fishermen for bait, is nearly a foot long, and is found on sandy parts of the coast, where it bores into the sand left wet by the retiring tide; its head is large and rounded, quite destitute of eyes or tentacula, and furnished with a short, unarmed proboscis. The feet are very small, and confined to the anterior part of the body, while the branchial tufts, which are of considerable size, are placed on each side of the middle segments." &mdash; Goodrich, 1859

Lob-worm

"Errantia means wandering, and is applied to numerous species, of which the Lob-worm or Lug-worm,…

"Arenicola marina. Entire animal viewed slightly from left side. Note anterior mouth; setae on anterior region; setae and gills on median region; thinner tail region often longer than shown." -Thomson, 1916

Lugworm

"Arenicola marina. Entire animal viewed slightly from left side. Note anterior mouth; setae on anterior…

A maggot with a rat like tail.

Rat Tailed Maggot

A maggot with a rat like tail.

"Tenebrio Molitor. Commonly known as the mealworm or the mealworm beetle. Common in Europe and in this country, of which the larva, found in flour, meal, etc., is well known as the meal-worm. It is common in mills, meal-tubs, granaries, and is distructive to sea-biscuit on shipboard." &mdash Goodrich, 1859

Mealworm

"Tenebrio Molitor. Commonly known as the mealworm or the mealworm beetle. Common in Europe and in this…

Meal Worm, Larva of a Flour Beetle.

Mealworm

Meal Worm, Larva of a Flour Beetle.

A moth larva eating fabric.

Moth Larva

A moth larva eating fabric.

A name to many common moths that are destructive to woolen fabrics, feathers, and furs.

Cloth Moth

A name to many common moths that are destructive to woolen fabrics, feathers, and furs.

The larva of the Grapevine Root Borer (Memthyrus polistiformis).

Grapevine Root Borer (Larva)

The larva of the Grapevine Root Borer (Memthyrus polistiformis).