A FEW FACTS ABOUT ZOOLOGY. 



distinctly marked by two or more feelers, with which eyes 

 are distinctly connected, as in the garden snail. 



Still among the mollusks, but a little higher, we come to 

 animals which have long arms or feelers around the head, 

 serving as organs, by which they move through the water 

 with a rapidity that is wonderful when compared with other 

 mollusks. In these animals the head is distinctly marked, 

 having a depression behind it; the feelers, such as we noticed 

 on the snail, do not exist, and the eyes (which are to be 

 found in the snail at the extremity of the feelers) are placed 

 immediately on the side of the head, and are very large in 

 proportion to the size of the animal ; this class includes 



cuttle-fishes, squids, and nautili. Few of these animals pos- 

 sess a shell; when they do, it is, with one exception, coiled, 

 not in a spiral, but from behind forward. Fig. 3 is a picture 

 of the pearly nautilus. Notice its bright eyes and long 

 feelers. The pearly nautilus has a peculiar shell, called a 

 chambered shell; the animal, as it grows, forms a wall be- 

 hind it at regular intervals, and always occupies the external 

 chamber, retaining, however, a connection with its past home 



