No. 4.] BILLINGS — FOSSILS OF NEWFOUNDLAND. 



469 



The shell which is supposed to be the ventral valve of this 

 species, is gently convex, with usually a somewhat flat space 

 extending from the front margin upwards towards the beak. 

 The apical angle appears to be from 90 to 100 degrees. Shell 

 very thick, of a lamellar structure, dark brown or nearly black, 

 and, sometimes, where exfoliated, of an ashy grey colour. Sur- 

 face with a number of obscure undulations of growth and with 

 fine longitudinal striae, about ten in the width of one line. 



Cruziana siMiLis, spec. nov. 



Fig. 6. Cruziana similis ; g, the median groove; V, r, the ridges at 

 the sides. 



The specimens are from twelve to fifteen lines wide, divided 

 along the middle by an angular groove, and bordered on each 

 side by a narrow ridge, about one line wide. The space on each 

 side between the median groove and the marginal ridg-es, are 

 moderately convex and crossed obliquely by numerous irregular 

 raised lines, with furrows between them. These lines usually 

 have the form of a gentle sigmoid curve, sometimes extending 

 quite across, but are often crowded together in a somewhat con- 

 fused manner, still preserving the general oblique direction. 

 Upon an average there are about ten lines in the length of half 

 an inch. The marginal ridges are sometimes longitudinally 

 striated. 



This species has been heretofore referred by me to C. semi- 

 plicata, Salter, but although closely allied, none of our specimens 

 agree exactly with the figures of the British species. 



Besides the above six species, many of the beds of sandstone 

 of Great Bell Island, are covered with several species of Palceo- 



