1878.] 29 [Rathbun. 



ence is greatly indebted for his constant support of the best interests 

 of the Geological Commission. 

 Spirifera, sp. indet. 



There is a single large dorsal valve of a Spi.ifera, which bears 

 some resemblance to those varieties of S. granuUfera of the Hamil- 

 ton group, having the cardinal extremities rounded. The surface 

 arches strongly and regularly from side to side, and also strongly 

 from the front margin to the beak, v/hich latter is prominent and 

 strongly incurved. There is no flattening at the cardinal extremi- 

 ties. Near the beak the fold is narrow, low, rounded, and marked 

 with a slight longitudinal depression along the middle. The hinge 

 line is slightly shorter than the width of the valve. There are, on 

 each side of the fold, thirteen or fourteen very low, rounded, almost 

 flattened plications, which are rather closely arranged, and the sur- 

 face is also marked with several rather strong lines of growth. The 

 width of this specimen is about 50 mm., length 38 mm. 

 Devonian sandstone, Erere. (Geol. Comm., 1876.) 

 Spirifera Valenteana Hartt, MS. 



Rathbun, Bull. Buff". Soc. Nat. Sci., i, no. 4, p. 241, pi. viir, 1874. 

 Of this species only one specimen has been found, the one from 

 which the original description was made. Devonian sandstone, 

 Erere. (Morgan Ex., 1871.) 

 Spirifera Harttii, sp. nov. 



Shell rather above the medium size, transverse, and with the pro- 

 portions of length to breadth about as 7 to 11 ; in outline transversely 

 subelliptical; hinge line slightly shorter than the width of the shell; 

 cardinal extremities rounded, the greatest width of the shell being 

 slightly anterior to the hinge line. 



Dorsal valve modei'ately convex, the surface rising with gentle, 

 regular curvature from the front margin to near the beak, toward 

 which it bends abruptly downward, causing the beak to be somewhat 

 flattened or apparently pressed down from behind. The valve is 

 slightly flattened at the cardinal extremities and for some distance 

 inward close to the hinge line, in front of which the umbonal region 

 is strongly inflated over a great width. From side to side, across 

 the middle, the curve of the surfoce is rather gentle and quite regu- 

 lar. The median fold is distinct quite to the beak, but on the poste- 

 rior portion of the valve it is not much elevated above the general 

 surface; it increases only gradually in height, but quite rapidly in 

 width, its width at the front equalling about one-fourth that of the 



