square in front. The creature is an Arctic form; it is extinct in the 

 EngHsh seas, though formerly existing there as it occurs fossil in the 

 Red and Coralline crag at Sutton, England, as stated by Jeffreys. 

 Further comparison should be made between the English fossil and the 

 New England form. 



The following species, Melampus bidentatus and Alexia myosotis 

 th4)ugh belonging to the Pulmonates, inhabit the sea shore and though 

 having no relation to the marine species of Gasteropods already 

 described are included here. 



ALEXIA MYOSOTIS Drap 

 PI. VII. Fig. 44. Length 7 mm. 



The body is white, short blunt tentacles with grayish axis, eyes 

 at the inner base of tentacles, head lobe sharply separated from creep- 

 ing disk. The creature is very sluggish in its movements. 



CARYCHIUM EXIGUUM Say 

 PI. VII. Fig. 45. Length 2 mm. 

 This creature, a land snail though living in wet places, is grouped 

 with Alexia and Melampus and is therefore included here. The 

 animal is white, tentacles very short and thick, rounded at tip, trans- 

 parent, a line marks the junction with the body. The eyes are rhom- 

 boidal in shape and are situated at the median base of the tentacles 

 in no respect bearing any relation to Melampus and Alexia. Its 

 habits are apparently the same as those of the English species, C. 

 minimum. Jeffreys figures the English species with bulbous ten- 

 tacles, like Helix, eyes on rounded supports and inside the base of the 

 tentacles. The shells of the English and American species are so 

 closely identical that the drawing in Jeffreys' must be entirely wrong. 



MELAMPUS BIDENTATUS Say 

 PI. VII. Fig. 46. Length 14imm. 



The animal is mouse-colored, tips of tentacles brown. The 

 tentacles are round, thick and retractile; eyes at inner base of tenta- 



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