HELIX. 195 



reddish-brown within ; whorls three, wrinkled, 

 with minute revolving lines. Largest breadth 

 about half an inch. 



parvus, (dwarf short-tail snail,) shell horn-colour 

 or blackish ; whorls four, crossed by minute 

 wrinkles ; concave above and beneath ; lip 

 rounded ; mouth bluish within. Breadth less 

 than the fourth of an inch. 



Section C. TAPERING HELIX. LYMN^IA of La- 

 marck. Spire terete, or conical. 



catascopius, (conk snail,) shell thin, horn-colour- 

 ed or blackish ; whorls 4 or 5 ; the first large 

 and swelling, and the remainder decreasing ra- 

 pidly to an acute apex, and are wrinkled cross- 

 wise ; aperture large, oval, not equalling three- 

 fourths the length of the shell. Breadth about 

 half an inch, length about three fourths of an 

 inch. 



heterostrophus, shell sinistral, subovate, pale yel- 

 low or brown ; whorls 4, first large, the other 

 tapering abruptly to an apex ; aperture large, 

 somewhat oval, three-fourths equal to the length 

 of th shell, pearly or blackish within, lips red- 

 dish. About half an inch broad and three- 

 fourths of an inch long. 



rinatuS) shell with three rounded subcarinate 

 whorls, reticulated with striae ; suture deep ; 

 apex truncate ; aperture oval, equal to more 

 than half the length of the shell. Length a lit- 

 tle over half an inch, breadth less. 

 rginica, shell tapering 4,0 the apex, and also a 

 little towards the base ; horn colour, blackish 

 or olive ; tinged with green under the epidermis 



