GONIOBASIS. 293 



Melania bizonalis. — Shell tapering, elongated ; whorls seven or 

 eight, flattened ; the upper whorls with a revolving, strongly cari- 

 nated line just above the suture, and above this two rig. 568. 

 slightly, but distinctly, elevated, revolving lines; all the 

 volutions with sinuous, vertical, elevated lines becoming 

 obsolete towards the tip ; aperture subovate, angular 

 above, and uniting with a broad, white callus on the pillar 

 lip; tip rarely perfect; color olivaceous-brown; epider- 

 mis with two and rarely three dark reddish, revolving lines on the 

 body-whorl, often indistinct, but may be traced. 

 Length, -7. Length of aperture, -23; width of aperture, -16. 

 Observations. — For this species I am indebted to Dr. Evans who 

 found it abundantly in Lake Champlain. It approaches Ifelania 

 Virginica, but is, as I view it, very distinct by its flattened whorls and 

 deep, angular sutures. — DeKay. 



Melania gemma. — Shell moderately large, oblong; spire attenuated, 

 acute ; the whole surface covered with waved, vertical Avrinkles ; 

 whorls eight, all distinctly carinate near the middle, and very acutely 

 so on the apical whorls ; on the lower whorls this carina is below the 

 middle, but becomes medial above, in some specimens the lower 

 Avhorls are bicarinate, or rather the carina is slightly furrowed on its 

 edge ; suture deep, occasionally cancellate ; the body-whorl has one 

 or more rounded grooves on each side of the carina, which produces 

 corresponding minute, elevated ridges ; lip fragile, its mai'gin convex, 

 rarelj^ perfect ; color variable from straw-yellow to amber and deep 

 reddish-brown ; columella often purple ; lower sutures opaque, white. 

 Length, •7-1-2 inches. Length of aperture, -23 of an inch. 

 Observations. — This species was obtained from Mud Creek, Onon- 

 daga County by Dr. Budd, and was at first referred to the semicarinata 

 FiK 5G9 °^ ^^Jy hitherto supposed to be an exclusively western 

 species. An attentive examination and comparison of 

 Say's description with this will exhibit strongly marked 

 differences. It is larger; all the volutions are carinate, 

 and the sutures distinctly cancellate. I have received 

 others from the Erie canal, much larger, being more than 

 an inch long. lu these the revolving groove, in descending, gradually 

 approaches nearer the suture, and is continued on the body- whorl, 

 which is vertically rugose. In my catalogue of species, I had named 

 this species after its discoverer, but the practice has been so much 

 abused, it is becoming daily obsolete. I trust that the name proposed 



