112 Biiiney on Terrestrial Mollusks. 



is one of those questions which it is quite impossible to 

 settle to the satisfaction of all jiarties, is proved by the 

 fact of my friend Mr. Thomas Bland having arrived at a 

 different opinion from mine, though furnished with the 

 same data. See Annals of N. Y. Lyceum of N. H. 1. c. 

 My decision is based on the following reasoning. 



With the exception of the minute species, Mr. Say was 

 acquainted with three shells only of this group, — Helix 

 lucubrata, inornata, and p^laphyra. The first mentioned 

 was found in a distinct zoological province ; consequently, 

 the question lies between inornata, as determined by Dr. 

 Bimiey, and the introduced cellaria. The figure given in 

 Nicholson's Encyclopaedia, rough as it is, can more readily 

 be referred to cellaria. The resemblance to that shell also 

 seems to have struck Mr. Say himself, since he speaks of 

 it in his remarks under its synonym H. nite?is, as he could 

 hardly do of the larger, less broadly umbilicated inornata 

 Binn. The pecuharity of its being "whitish beneath," oji 

 which Mr. Say lays particular stress, is more constant in 

 cellaria. The description would apply equally to both, 

 with the exception of " umbilicus moderate, not exhibiting 

 the volutions." As regards this phrase, I must say that it 

 seems to contain a contradiction ; since any shell must 

 show its volutions more or less in the umbilicus, if it is at 

 all open. A minute perforation, as it is now called, would 

 not show them ; but all Say's perforated species are desig- 

 nated as having a "small" umbilicus. The term " mod- 

 erate" is applied by Say to the umbilicus of H. tridentata 

 in the same paper in which the description of g-lap/iyra 

 occurs, and subsequently he applies it to H. septemvolva 

 alone. The only terms he uses for the umbilicus of his 

 species is " small," " large" or " very large," and " moder- 

 ate." After a very careful study of his descriptions, I am 

 convinced he used the words " umbilicus moderate, not 

 exhibiting the volutions," in a comparative sense, in con- 



