3G0 JZemarks on Certain Species of 



" It cannot be confounded with any other than H. albolabris, and dif- 

 fers from it in the following particulars : — It is much more globose, of a 

 coarser and more solid texture, and the striae of increase are much more 

 raised and prominent, so much so, indeed, as to leave distinct grooves 

 between them. The revolving stria?, so distinct on that shell, are either 

 wanting or very indistinct. The aperture is smaller in proportion to the 

 size of the shell, less flattened towards the plane of the base, and more 

 rounded. The pillar lip and umbilicus are in many instances covered 

 with a smooth and shining, semi-transparent, testaceous callus. The 

 margin of the lip is thickened, the lip itself is narrower, less abruptly 

 reflected, and not so much flattened, and there is often a tooth-like pro- 

 cess on the inner and upper side of the margin near the umbilicus. The 

 color of the epidermis is generally much darker. The only considerable 

 variation in the characters of the shell is caused by the depression of the 

 spire in some individuals, and indeed in all specimens from certain locali- 

 ties. In its most perfect condition it is often subconical. It is subject 

 to some irregularities in the form of the mouth, and there is sometimes 

 an indication of pale bands in the epidermis of the body whorl." 



He adds, — 



"That this is not the same species increased in size by the influence 

 of a warmer climate, would seem to be proved by the fact that other 

 species are not larger in Florida than in situations further north, and 

 that H. tridentata Say, common in every part of the country, is smaller 

 in Florida than elsewhere. The color of the respective animals is widely 

 different." 



Dr. Binney's illustration as to the influence of climate is an 

 unfortunate one. In the Boston Journal lie makes the same 

 remark, mentioning, however, //. fallax, instead of II. triden- 

 tata, and with his notes on the latter (which he erroneously 

 treats as identical with the former), he figures (pi. 18, fig. 2) 

 as " the small variety from Florida " of tridentata, a distinct 

 southern species, which never attains a much larger size, viz. 

 the II. Ilopetonensis of Shuttleworth, who, in its synonymy, 

 refers to that same figure. 



