ENCOURAGEMENT. 67 



student lose heart, and say that the study of mollusks 

 is too difficult a subject to be engaged in by any one 

 who is not an enthusiast or a prodigy. Shells only 

 an eighth of an inch in length, and rare at that, are 

 hardly worth the seeking, I fear some one is saying. 

 Well, do not be discouraged, nor leave off the study 

 on this account. All these little creatures live in the 

 great ocean, and all deserve mention ; for some one 

 will find them and wish to know what they are. If 

 from this book you can learn the probable names, the 

 larger works will give you information respecting the 

 genera, and will enable you to study their relation- 

 ships and affinities. 



But if you neither have time to look up the little 

 shells, nor opportunity to study about them in the big 

 books, you can surely find some of the shells which 

 I am about to describe. 



When you went to the seacoast, and climbed among 

 the rocks where the waves were throwing up their 

 spray as the tide came in, you surely saw numbers of 

 dark-colored shells about the size of peas. You found 

 them in the cracks of the rocks, along their sides, 

 and concealed in every little nook and cranny. Their 

 shells are dull — somewhat like the rocks themselves ; 

 the apertures are closed with horny opercula, and the 

 animals seem to be asleep. But put some of them 

 into a jar of sea-water, and in a little while the little 

 black snails come creeping out, and begin to work 

 their way up into the air again. 



These little Iyittorines, as we will call them, are 

 the first mollusks we meet as we go down to the 

 shore. The upper part of the beach is known as the 

 littoral region, so you see how the mollusks get the 

 name of Iyittorine. They live out of the water most 



