CHAZY LIMESTONE. 33 



ornamented appearance as represented in fig. 10. The aperture is transversely oval, or 

 somewhat rounded, and compressed upon the ventral side. The shell is readily distinguished 

 by its beautifully ornamented surface, absence of dorsal carina, and the acutely angular 

 edges of the inner whorls. 



Fig. 10. Dorsal view, looking into the aperture, which is filled with stony matter, so that the form can 

 not well be shown. The shell is denuded from a large portion of the last volution, but is 

 well preserved on the part exhibited in the figure 



Fig. 10 a. Lateral view of the fossil denuded of the shell ; the cast smooth. 



Position and locality. This species occurs in the lower fine-grained limestone of Chazy, 

 and I have seen fragments with similar markings from other localities. Chazy, Clinton 



county. (State Collection.) 



58. 2. BUCANIA ROTUNDATA. 



Pl. VI. Figs. 11 a, i, c. 



Convolute, suborbicular or spheroidal ; outer whorl ventricose, angular, expanding 

 towards the aperture ; inner ones appressed, angular at the sides ; surface marked by 

 transverse striae or lines of growth ; aperture suboval, compressed on the ventral side by 

 the contiguous whorl. 



This shell is more rotund than the last ; the inner volutions are less angular, and the 

 external surface is marked only by faint transverse striae or lines of growth, with a few 

 stronger wavelike lines. There is no indication of a carina, or of a depressed line along the 

 back of the shell. The whorls are not involute, but closely pressed against each other ; the 

 dorsal side of the inner is pressed to the ventral side of the outer, forming a broad groove 

 or depression. 



Fig. 11 a. Dorsal view, looking into the aperture, which is partially filled with stony matter, and broken 

 at the sides. In this view, it presents the aspect of a Bellerophon. 



Fig. 1 1 b. Side view ; the volutions not all visible, from the umbilicus being filled with stony matter. 



Fig. 1 1 c. Longitudinal section, showing the form and relation of the volutions to each other ; the dotted 

 line is the margin of the outer volution near the aperture. 



Several individuals of this species have been seen in the Chazy limestone ; and, so far 

 as known, it is confined to this rock. 



Position and locality. In the fine-grained and partially oolitic limestone of Chazy, 

 Clinton county. 



[ Pal.eontology.] " 5 



