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Genus Bellerophon, Montfort. 

 Bellerophon vinculatus (n. sp.) 



Shell of medium size, subglobose ; the diameter of the axis a little 

 greater than that of the plane of the shell. Dorsum marked hj a 

 proportionally broad band, bounded on each side by an elevated 

 flattened line. Sides of the shell marked by transverse bands, which 

 rise from the edges of the revolving band, and pass with a gentle 

 forward curve toward the axis, where they become obsolete. These 

 bands are elevated on the forward margin and depressed on the 

 posterior, presenting the appearance of a succession of low steps. 

 Centre of the revolving band marked by a succession of retrorse 

 curves, which are a continuation of the transverse bands that have 

 been interrupted by the revolving lines. Margin of the aperture 

 gently curving backwards from the axis to the middle, where it is 

 deeply notched. 



This species very closely rasembles B. hicarenus^ Leveille, DeKon- 

 inck's Anim. Foss., pi. 28, fig. 8, but the transverse bands are not more 

 than half the number, in the same space, and our shell is not 

 umbilicate. 



Bellerophon perelegaxs (n. sp.) 



Shell small, subglobose ; umbilicus small, aperture transverse, reni- 

 form. Back and sides marked by fine, sharply elevated revolving 

 lines, which are about equal to the spaces between them, finer and 

 more closely arranged in the middle than on the sides of the shell. 

 Dorsum marked by a narrow, elevated, revolving band ; bounded on. 

 each side by a shallow depression. The revolving lines on the band 

 are much finer than those on the body of the shell. Very fine trans- 

 verse striae of growth across the revolving strias, giving a finely cancel- 

 lated appearance to the surface. Margin of the peristome nearly 

 straight, or with a gentle backward curvature to the shallow central 

 notch. 



This species resembles B. cancellatus, Hall, of the Warsaw division 

 of the Carboniferous Limestone, from Spergen Hill, Ind., but the 

 revolving striae are much coarser, and unequal in difierent parts of the 

 shell ; and the transverse striae are finer, while the revolving band is 

 much more distinct. 



Bellerophon bilabiatus (n. sp.) 



Shell of medium size, the inner whorls subglobose, the outer with a 

 narrow, sharp carina on the back, and a broadly-expanded peristome, 

 which becomes somewhat reflexed near the border, and deeply notched 

 in the middle, giving to the aperture a strongly bilobed outline ; umbil- 

 icus large. Surface smooth, except a few &int undulations, which 



