140 THE NAUTILUS. 



little marked sinuosity at the outer upper angle ; lamellae : apertural^ 

 more simple than in some other species ; inferior palatal placed and 

 shaped as usual. 



This well defined species has been found from South Carolina and 

 Florida to Louisiana, always near the coast. I have not seen it from 

 the West Indies. — Synonymy and references will be found with the 

 following : 



Piipa procera Gould. 



When Dr. Gould published this species/ he knew it only from 

 Baltimore specimens. Subsequently it was considered identical with 

 P. rupicola Say. After having examined and compared many hun- 

 dreds, even thousands of examples of both species, I came to the con- 

 clusion that they are quite distinct ; and I never saw a doubtful or 

 intermediate specimen. The author's description leaves no doubt 

 as to the identity of the species. 



P. pj'ocera is characterized by its cylindrical, rather strong shell 

 with obtuse apex, the uniformly brownish horn to chestnut color, 

 and the form of the aperture ; one peculiar feature which has been 

 pointed out by Gould," is the deep seated and rather transverse in- 

 ferior lamella in the palatal wall. 



In Binney Terr. Moll. II, p. 339, under the head P. rupicola, the 

 description is of P. procera, and so are the figures of the aperture ; 

 the same is in W. G. B. Bulletin No. 28. In Gould (W. G. Bin- 

 ney edit.) Mass. Invertebr. 1870, under P.rnpicolaSay, the descrip- 

 tion is of P. pjrocera, while the figure represents ritpicola. There is 

 no doubt but that Mr. W. G. Binney, as well as Pfeiffer and others, 

 had not a sufficient number of good specimens before them, of one 

 or either species, or they would have arrived at a different conclu- 

 sion. 



Our species is the only one of the subgenus living remote from 

 the sea in the interior of the continent. It is distributed over a 

 great part of our country. Its area is from New England and 

 South Carolina to jNIinnesota and Texas, and in this whole region it 

 is remarkably constant. Only some Iowa and Minnesota examples, 

 from Winona, are somewhat smaller and more delicate, the aper- 

 tural lamella showing a more marked configuration. 



1 Monograph of . . . Pupa, Boston Journ. Ill, p. 401, pi. 3, f. 12; IV, 

 pi. 16, f. 12, and p. 355. 



2 1 c. 



