Description of a New Genus of PimelodincE, (&c. 39 



and many, without mention of habitat, from several coiTespon- 

 dents. 



Observations. — ^This species, the aperture of which is repre- 

 sented in Fig. v., is common in American cabinets, and usually 

 labelled IT. avara, or var. of H. auricidata, but it Fig. V. 



appears to me entirely distinct. It is most nearly 

 allied to the former, but is larger, not hirsute, and 

 has the groove in the last whorl, within the 

 umbilical region like the latter. The parietal fold is some- 

 what similar to, but does not descend so far into the aper- 

 ture as that of i/". Postellania, but the teeth on the labrum are 

 in form and position, though more developed, rather like those 

 of H. avai'a. They are separated by the same deep sinus, but 

 the upper one generally without the sharp reflexed hook at its 

 termination. 



The pale and white varieties are, I believe, from Alabama, 

 — my figure is taken from one of them, the shells are 

 heavier, and the parietal fold especially is more developed. 



I have given to this species the name auriformis, the general 

 form of the aperture, with its several parts, offering a more 

 striking resemblance to the human ear than is the case with 

 any of its allies. 



VIII. — DesGription of a New Genus of Pimelodinm from 



Canada. 



By Theo. Gill. 

 Read January 31, 1859. 



Synechoglanis, Gill. 



Body moderately elongated and much compressed, with the 

 back and abdomen very slowly converging to the adipose fin ; 

 caudal peduncle moderate behind the anal fin. 



