GRAND DIVISIONS. 44 
sensible and furnished with a liquid hamor which 
issues from its pores. 
Molluscous animals are generally covered with 
plates of carbonate of lime, which serve as beds 
er retreats from danger. ‘These plates, usually 
ealled shells, are produced by secretion from the 
skin. The process of reproduction greatly re- 
sembles that of plants with perfect flowers ; rare- 
ly that of dicecious flowers. 
Animals of this division, though more compli: 
cated in their digestive and circulatory system 
than animals of the articulated division,* seem 
to have been cotemporaries with the oldest of 
the radiated division. For we find the remains 
of several species of this division in the oldest 
transition rocks, which rarely if ever, contain any 
relics of the articulated or vertebral divisions. 
Examples. Nautilus, snails, oysters, barni- 
cles. 
Hit. ARTICULATED ANIMALS. 
In this division the sentient principle is lodged 
an two lons cords, swelling at tervals into knots 
or ganglyous, extending through a jointed body 
in the longitudinal direction. The organs of sense 
and motion are all double,and arranged on two 
sides of the nervous axis. | 
The principal ganglyon is placed near the 
throat. They have jointed trunks or abdomens ; 
and all but one class, have jointed limbs articula- 

* Cuvier places this division between the vertebral and articulated, 
en account of the greater perfection of the residence of the sentient 
principle. For if the bee is more active than the oyster, so the cat 
and pigeon are more active than man. But we have changed the or- 
der to accommodate it to the study of petrifactions and shells ; for very 
few have the means for studying the anatomical structure of mellus 
ceous animals, 
