270 NEW UPPER CAMBRIAN FOSSILS WALCOTT. 



Formation and locaUttj. — Associated with tbe preceding species. Col- 

 lector, C. 1). W. 

 Nat. Mus. Cat. Invert. Foss., L*3S51. 



Hyolithes ? corrugatus sp. nov. 

 Plate XX, Fig. 9, 



Shell, an elongate, gradually and regularly tapering, obscurely sub- 

 triangular cone. Transverse section oval and somewhat tlattened on 

 one side, so as to give it a subtriangular form in some specimens. It is 

 difiScult to determine the dorsal and ventral faces in the absence of the 

 aperture. Shell, strong; surface marked by iDrominent corrugations 

 or undulations that are a little oblique to the longitudinal axis; they 

 occur on the flattened sides and are not continuous across the narrow 

 portion. There is also considerable variation in their depth and width, 

 the interior "casts usually showing the strongest undulations. 



This shell does not appear to be a true Hyolithes. In many respects 

 it is more closely related to Coleoprion or Coleolus, but varies in essen- 

 tial particulars. While awaiting further study a provisional reference 

 is made to Hyolithes. 



Formation and locality. — Associated with the two preceding species. 



Nat. Mus. Cat. Invert. Foss., 23852. 



Hyolithes newtoni sp. uov. 

 Plate XX, Fig. 4. 



Form, an elongate, triangular pyramid. Transverse section subtri- 

 angular, slightly concave on the dorsal, and very convex on the ventral 

 side. Dorsal face rounded on the margin and concave all across; ante- 

 rior extension unknown. Ventral face highly convex and rounded 

 along the median line. Aperture and operculum unknown. Shell 

 apparently thick, but this is probably owing to the mode of preserva- 

 tion, as in a few specimens it is thin. Surface of shell as far as known 

 marked only by a few concentric strire. 



The concave dorsal service taken in connection with the general out- 

 line serves to distinguish this species from others known to me. 



Formation and locality.— XJpixiv Cambrian, near Headwood, Black 

 Bills, Dakota. Collected under charge of Prof. F. R. Carpenter. 



Nat. Mus. Cat. Invert. Foss., 23849. 



Conularia cambria sp. uov. 

 Plate XX, Fig. 10. 



Form, an elongate pyramid, with a quadrangular 'I base. Transverse 

 section and aperture unknown, owing to the flattening of all the speci- 

 mens. Angles of the pyramid marked by a very distinct groove. 

 Faces of the pyramid slightly convex in the flattened specimens. 



