46 Cincinnati Sociefy of Nalural History 



Tripteroceras laynbi was described as from the Trenton or 

 Black River strata at East Selkirk, in Manitoba, but in liass- 

 ler's Bibliographic Index the possibility of the East Selkirk 

 horizon belonging to the Richmond is indicated. Clarke 

 identified with this species a closely similar form from the 

 middle Galena at Stewartsville, Minnesota, but here also 

 Bassler questions the reference of the horizon to the Trenton. 



Conchopeltis miseneri, sp. nov. 

 Plate I, Figs. 4 A, B 



Shell patelliform, with an upturned beak, the curvature 

 of the shell immediately posterior to the beak being concave, 

 the concave tendency remaining as far as the posterior margin 

 of the shell, but to a lesser degree. Possibly there is also a 

 slightly concave curvature from the beak forward, toward the 

 anterior margin, but this can not be determined definitely 

 from the specimen at hand. From the beak two grooves 

 extend forward, one on each side of the shell, forming angles 

 of about 150 degrees with each other. Anterior to these grooves 

 (marked A, A, in figure 4 on plate I), the shell is compara- 

 tively smooth or is marked only by obscure and narrow radi- 

 ating plications. Posterior to these grooves the shell is strongly 

 and radiately plicated. Of these plications there are eleven. 

 The anterior pair, one plication on each side of the shell, is 

 almost as broad as the third pair, but the crest lies nearer the 

 posterior margin. The second pair (marked B, B, in the 

 figure) is conspicuously narrower. The remaining plications, 

 seven in number, are strongly convex, and are separated by 

 comparatively deep concave grooves. The entire shell is 

 marked by concentric lines of growth. These lines indicate 

 that the general outline of the shell was oval or nearly circular, 

 and not quadrilobate as in Conchopeltis alternata, Walcott, 

 from the Trenton limestone of New York, the type species of 

 the genus. In the species here described there may have been 

 a slight indentation of the margin of the shell at the ends of 

 the anterior grooves (marked A, A, in the figure), giving the 



