COMPARATIVE ANATOMY. 
a long' nervous chords beset with ganglia ; 
compound eyes ; antennae and palpi like 
those of -insects; a heart and circulating 
vessels, and gills ; teeth in the cavity of the 
stomach. 
1. Cancer, crab, lobster, crayfish, 
shrimp, 
g. Monoculus. 
Insects have articulated members and 
antennae. Those which fly are subject to 
what is called a metamorphosis; they pass 
through certain intermediate states of ex- 
istence, before they assume the last, or per- 
fect form. From the egg proceeds the lar^ 
va, or caterpillar; this changes to the chry- 
salis, nympha, or aurelia, from which the 
perfect insect is produced ; nervous system 
consisting of a chord beset with ganglia ; 
no heart nor blood-vessels ; respiration car- 
ried on by means of tracheae. 
Order I. Coleoptera ; having a hollow, 
homy case, under which the wings are 
folded. 
1. Scarabreus, beetles, 
g. Lucanus, stag-beetle. 
3. Dermestes. 
4. Coccinella, ladybird. 
5. Curculio, weevil. 
6. Lampyris, glow-worm. 
7. Meloe, Spanish-fly. 
8. Staphylinus. 
9. Forficula, earwig. 
II. Hemiptera ; four wings, either stretch- 
ed straight out, or resting across each other. 
1. Blatta, cockroach, 
g. Gryllus, locust, grasshopper. 
3. Fulgora, lantern-fly. 
4. Cimex, bug, &c. 
III. Lepid«ptera; soft hairy body, 
four expanded wings. 
1. Papilio, butterfly. 
Sphinx, > 
1 ). > 
and 
Phatena 
IV, Neuroptera ; four reticulated wings. 
1. Libellula, dragon-fly. 
2. Ephemera, &c. 
V. Hijmenoptera ; generally possessing a 
sting. 
1. Vespa, wasp, hornet. 
2. Apis, bee. 
3. Formica, ant. 
4. Termes, white ant. 
5. Ichneumon, &c. 
VI. Diptera ; two wings. 
1. CEstrus, gad-fly. 
2. Musca, common flies. 
3. Culex, gnat, mosquito. 
4. Hippobosca, horse-leech, &c. 
VII. Aptera ; no wings. 
1. Podura, springtail. 
2. Pediculus, loiise. 
3. Pulex, flea, chigger. 
4. A earns, tick, mite. 
5. Aranea, spiders. 
6. Scorpio, scorpion, &c. 
The vermes may be divided into two 
orders ; the intestinal, which inhabit the 
bodies of other animals ; and the external. 
The former are not of such a complicated 
organization as the latter ; so that they are 
sometimes arranged among the zoophytes. 
Tlie external worms have a nervous chord 
possessing ganglia, an elongated body com- 
posed of rings, and having no distinct head ; 
there are no members ; circulating vessels, 
but no heart; no nerves havei been dis- 
covered in the intestinal worms. 
Order I. Intestini. 
t. Gordius, guinea-worm. 
2. Ascaris, thread-worm, round- 
worm. 
3. Tricocephalus. 
4. Fasciola, fluke. 
5. Taenia, tape-worm. 
6. Hydatis, hydatid. 
II. Externi. 
1. Aphrodite, sea-mouse. 
2. Sipunculus. 
3. Hirudo, leech. 
4. Nereis. 
5. Nais. 
6. Planaria. 
7. Lumbricus, earthworm, &c. 
The Zoophytes have neither brain nor 
nerves ; no heart, nor, perhaps, blood-ves- 
sels ; no articulated members. 
Order I. EchinodermaUt ; covered by a 
hard and tough coriaceous skin. 
1 . Echinus, sea hedgehog. 
2. Asterias, star-fish, &c . 
II. Soft or Gelatinous Zoophytes. 
1. Medusa, sea-blubber, sea-nettles. 
2. Actinia, sea-anemone. 
3. Hydra, fresh water polype. 
