306 



LOWER INVERTEBRATES. 



Fig. 349. — Scarabus 

 /asciatus. 



The Auriculidae are mostly found in the neighborhood of the sea, especially in salt 

 marshes. The genus Auricula, from ■which the family derives its name, has but a very 

 remote resemblance to an ear ; the species are all inhabitants of 

 brackish-water swamps in tropical regions, and are characterized 

 by an absence of teeth on the outer lip of the long and narrow 

 aperture. In Scarabus the shell is laterally compressed, so that 

 the edges are angular ; the aperture would be lai-ge were it not for 

 the teeth which arise from both lips, and the spire of the shell is 

 acute. The species all come from the tropical parts of the eastern 

 hemisphere, where they live in the woods near the shore. 



Alexia is represented in the United States by a single species, 

 A. myosotis, which does not extend farther south than New Jersey. 

 In Europe it is found on the shores of the Atlantic and the Medi- 

 terranean. It frequents places where it is covered by the tide for 

 several hours each day, moving in , , . ^ i , 



a very sluggish manner. Fresh 

 water kills it. Other species are 

 found in Europe and the West 

 Indies. The shell is of a general 

 dark horn color and bears two 

 tooth-like folds on the columella. 

 Carychium is much like Pupa in 

 shape, and our single species, C. ex- 

 iguum, is widely distributed under 

 stones and moss in damp places, 

 and is the only member of the 



family which in the United States is found far from the sea. 



In the species of Melampus the shell is ovate in outline, the spire 

 short, and the outer lip acute. Four species are found in the United 

 States, one on the Pacific and three on the Atlantic coasts. One of 

 the southern forms has received the specific name coffea, from its re- 

 semblance in size, shape, and color to a kernel of coffee. This species and an- 

 other, M. flavus, occur in the United States only in Florida, except 

 when introduced elsewhere by means of vessels trading with southern 

 and West Indian ports. The remaining species, M. bidentatiis, is com- 

 mon in the grass of every salt marsh from Massachusetts to Texas. 

 When young, this is a very pretty species, being brownish in color, 

 marked with revolving reddish bands, and the whole highly polished ; 

 but the adults are dirty and eroded. The length of a large specimen is ^cfi^'^gSi. 

 about half an inch. 



§The species of Cassidula have a subquadrate body whorl and very 

 short spire ; and the outer and inner lips are toothed. The species all 

 belong to the Indo-Pacific region, frequenting mangrove swamps and 

 Fig 353 —Me- '^'^'^^J shores. The species of Pedipes are all tropical and sub-tropical. 

 taS"* ^^"^ They have a looping gait like that of a measuring worm, and with this 

 peculiarity in locomotion is correllated a transverse groove on the foot. 

 The members of the genus are among the most active of molluscs. No species occur 

 in the United States, the nearest approach being Lower California, where P. lirata 



Fig. 350. — 5cara6tts imbrium. 



Fig. 351. — Al- 

 exia myosotis. 



