38 CLASSES. 
Examples. Tortoise, lizard, snake, frog, sal- 
amander, proteus, siren. 
4. Pisces, oviparous, having fins, and no feet. 
Heart with one ventricle, blood cold, gills sub- 
stituted for lungs, covering imbricate scales. 
Examples. Sturgeon, sunfish, pipefish, shad, 
bullhead. | 
ARTICULATED ANIMALS 
ARE DIVIDED INTO FOUR CLASSES, 
5. Annevipa, without a bony skeleton and hav- 
ing red blood Body soft, elongated ; covering di- 
vided into numerous tr nsveErse rings. 
Mostly living in water. Some of them secrete 
calcareous matter, which forms a stony, tubular 
covering. 
Examples. Earth-worm (angle-worm) sea- 
pipe, leech, hair-snake. 
6. Crusracres, animals with jointed hmbs, 
which are articulated to a hard calcareous crust. 
They respire by a kind of gills. 
_ Their gills are pyramidal, made up of plates, or 
bristly with threads, plumes or simple plates. 
They generally occupy the base of the feet. ‘They 
have mostly four antennz, ten feet and six jaws : 
one under lip is always wanting. 
Example. Lobsters, crabs, horse-hoofs. 
7. ARACHNIDA, animals with jointed limbs, with- 
outantenne They respire by little openings ator 
near the termination of the thorax, which lead to 
organs resembling lungs ; or by little trachee or 
pipes distributed over the whole body. 
- The head and thorax are blended together, 
They have mostly six or eight eyes, and eight 
