PUPA. 315 



tutcs another well-marked group, if not a distinct genus, 

 they arc so superior in size, and so different in their 

 habits, choosing the vicinity of salt water, and even 

 places dashed by salt spray, rather than forests or locali- 

 ties kept moist by fresh water. 



Most of the species are so small that it requires much 

 care and no little skill to find them. Some are found in 

 forests, under decaying leaves, or fragments of dead 

 branches, lying on the ground, or in the crevices of bark, 

 or about decaying stumps and logs ; some are found in 

 plats of moss, others under stones, sticks, etc. in the open 

 fields ; and many at the margins of brooks, pools, and 

 ponds, under chips, or crawling up the stems of plants, 

 and seem to be incapable of existing unless abundantly 

 supplied with moisture, seeming to be aquatic rather 

 than terrestrial in their habits. They feed on decaying 

 vegetable matter, keeping themselves in the shade, and 

 adhering closely to the objects on which they rest when 

 in repose. In the winter they bury themselves under 

 the leaves or in the earth. These little shells possess 

 great beauty, and well repay a careful study. When 

 largely magnified they show a great variety and compli- 

 cation of parts, all wrought to the highest perfection of 

 form and polish, and forcibly illustrate the skill of the 

 great Creator. [G.] 



