MOLLUSCS, VERMES AND HYDROZOA 



with usually five yellow bands, more distinctly marked on the body whorl 

 It has four to five 

 convex whorls, the 

 first a mere dot and 

 the body whorl very 

 wide and exceed- 

 ing half the shell 

 in length. All are 



rounded and sharply fig. 145. Georgia Snail, ymiparus georgianus. 



defined, with impressed suture. The operculum is bluntly pearshaped 

 and thick, with well defined lines. The body is dark brown, spotted 

 with yellow, the snout broad and the tentacles long and divergent. The 

 eyes are placed on the outer bases of the tentacles. It is ovoviviparus and 

 harmless to aquatic plants when sufficiently fed, and bears a close resem- 

 blance to the foregoing. Quite generally distributed throughout the Middle 

 and Southern States; first found at Hopetown, Georgia. Known as the 

 Georgian Snail. Also note the Japanese Snail, V. malleatus hereafter 

 described. 



Campeloma. These snails inhabit still water and slow-flowing 

 streams. The shells are thick, heavy and about as long, but narrower than 

 the foregoing, and the whorls flatter and not as rounded. The larger 

 Eastern and Middle States species rarely exceed i Y^ inches in length and 

 most of the specie^ less than ^ inch. 



C. decisum. Fig. 146, is common in ponds and nearly all freshwater 

 in the Eastern section of North America, from Nova Scotia to the Rio 

 Grande. The i/^ to i inch long shell is elongate-ovate, rather thick and heavy 



with a smooth surface not 

 very considerably marked 

 by lines of growth. Its 

 color is greenish with ir- 

 regularly disposed brown 

 lines of growth and is 

 usually eroded at the apex 

 so that of the five whorls 

 sometimesbuttwoor three 

 FIG. 146. Campeloma decisum. remain. The body whorl 



is about two-thirds the length of the shell, the aperture oval-oblique more 

 than half the length of the body whorl, and the operculum is elongate- 

 ovate with a thin transparent margin. It is ovoviviparous and harmless in 

 the aquarium, though a considerable feeder and should be furnished with 

 food in addition to the algae and confervse. 



It is found in streams in New 



223 



