312 



Of the specimens referred to in this quotation, the only one that the 

 writer has seen is the fossil from La Petite Chaudi^re that has been 

 rubbed down on one side and polished in such a manner as t,o exhibit the 

 " artificial polished section " described by E. Billings. This specimen, 

 which is now figured for the first time (figs. 1 and la) is evidently in- 

 tended as the type of the species, though it shews little more than the 

 mode of coiling and the lateral compression of the whorls. 



Of late years a few imperfect specimens, that are apparently referable 

 to this species, have been collected at La Petite Chaudiere, on the Quebec 

 side of the Ottawa River, at Tetreauville, by Mr. W. R. Billings, Mr. J. 

 E. Narraway, and the writer. One of these specimens, the original of 

 figs. 2 and 2 a on Plate 40, is an imperfect cast of the interior of the 

 septate portion of the shell. It shews that on the convex exterior of the 

 cast, each of the sutural lines forms a single, widely and very shallowly 

 concave sinus or " lobe " on each side, and a low, simple, undivided and 

 obtusely subangular saddle on the venter. On the dorsum, also, there 

 are indications of a similar saddle. It seems to the writer that the few 

 specimens of Gyroceras ('or Lituites) vagrans that have yet been obtained 

 are clearly congeneric with Barrandeoceras convolvans, and B. subcostu- 

 latum. 



Figures 3 and 3 a were inadvertently printed on Plate 40, because the 

 writer was at first under the impression that the original of both was 

 also a fragment of a specimen of B. vagrans. But it soon became appa- 

 rent that this fragment is a piece of a specimen of a Cyrtmceras, and most 

 probably of C. sinuatum, Billings, the type of which is a badly preserved 

 cast of the interior of a shell, also from the Black River limestone at La 

 Petite Chaudiere. The exterior of this fragment (figure 3) shews that 

 the surface ornamentation consists of narrow, transverse and slightly 

 flexous ribs, with wider spaces between them ; and the inner portion 

 (figure 3 a) which has been broken in such a way as to exhibit a longitu- 

 dinal and nearly median section, shews that the siphuncle is placed a little 

 outside of the middle, or, as Hyatt, would have said, somewhat ventrad 

 of the center. 



