32 1>AL£ONTOU)OT OF NEW-TOSK. 



66. 1. MURCHISONIA ABBREVIATA. 

 Pu VI. Fig. 7. 



Terete-conical ; length about twice the breadth ; whorls few, appressed, angulated ; 

 marked by advancing and rcti^^ting striee. 



A single specimen of this shell was found at Chazy, but it was unfortunately lost after 

 the drawing was made. It seems appropriately referred to the Genus Mukchisonia, which 

 includes the elongated Pleurotomaria-like shells, of which there are several species in the 

 lower strata. 



Position and locality. In the lower fine-grained limestone. Chazy, Clinton county. 



Genus BUG AN I A. 

 [Greek, /3w(ov»i, a trumpet; from the form of the shelL] 



Character. Convolute ; spire equally concave on either side ; volutions in the same plan^, 

 all visible, outer one ventricose, inner ones usually angulated on the edge, concave on the 

 ventral side ; aperture rounded-oval, somewhat compressed on the inner side by contact 

 with the next volution, laterally and dorsally abruptly expanded. 



This genus is proposed to include several species of shells of a peculiar form, usually 

 referred to Bellerophon, but from which they difier in having all the volutions visible, 

 and gradually increasing in size. The Bellerophon cornuarietes of Sowerbv ( Min. Conch. 

 Tab. 469, fig. 2 ), will fall under this genus. At least six species are already known to me, 

 and these are confined to the lower term of the system, none as yet having been observed 

 in the higher strata, though the one quoted above from Soweeby is said to occur in the 

 Mountain limestone. 



This genus differs from Porcellia, in being symmetrical, the volutions in the same axi^ 

 being equally expanded on either side, both sides presenting the same aspect, and the 

 aperture corresponding to the axis of the shell. 



37. 1. BUCANIA SULCATINA. 



Pu VI. Figs. 10. 10 a. 

 BeUerophon nUcatinui. Eiuioifg, Geol. Report, pag. 312, fig. 4. 



Convolute ; depth and width nearly equal, length a little greater ; whorls closely 

 appressed against each other, and angulated on the sides ; surface marked by longitudinal 

 ridges, which are interrupted by obliquely transverse lines, the latter making a retral angle 

 on the depressed dorsal line. These ridges are often subdivided into two or more undulating 

 lines, and which, from being interrupted by the transverse lines, give the shell a beautiful 



