- i:^L. - 



er SToecirnens of hiSDaiiiolla nay be diie to the ^xrioertsinties of 

 of Gollection, but it is possible that the ^voung forins differ so 

 li-^tle from halidonata that they cannot be separated. 



The Santo Doming-lan forms that G-abb determined as A_, oonsobrina 

 Sov;erbj- are typical, but to place A. florid ana J onrad in synonymy 

 v/as an error. It is orobably safe to suspect that the citation 

 of Guppy for the occurrence of oonsobrina in"Haiti" refers to 

 hispaniolia , but it is i-incertain whether the Jumana specimens are 

 halidonata or its variety; 7abb's Oosta Siean Pliocene oonsobrina (l) 

 is scarcely the same as the Santo Dominorian fonii, being- higher and 



(1), Jour. Acad. TTat. Sci., Philadelphia, 2nd ser. , vol. 8, p. 

 378. 1881. 



more convex. 



Toula is mistalcen in assigning consobrina to Moore, whose 

 description of "Some Tertiary Beds in the Island of San Domingo" 

 immediately preceeds Sov;erb^ 's description of the shells. The 

 single Gatun specimen is go poorly preserve! that it is difficult 

 to determine what it actually is. Toula comments on the marked 

 dichotomy of the posterior ribs, a feature which is most character- 

 istic of hispanioli a. 



'The Miocene (Duplin) and Pliocene (Waceamaw and Oaloosahatchie ) 



