Subcarboniferous Fossils from New Mexico. 313 
CAMAROPHORIA OCCIDENTALIS, Nn. Sp. 
Plate VII., fig. 7, dorsal view ; 7a, ventral side; 7, front view. 
Shell of variable size, some in the collection having less than one 
fourth the dimensions of the specimen illustrated. General form sub- 
trigonal, wider than long, truncated in front, straight upon the postero- 
lateral slopes and rounded to the front. Dorsal valve gibbous, most 
convex anteriorly. The posterior lateral slopes are abrupt, the anterior 
lateral slopes and the front are more or less sharply geniculated, and 
extend down, meeting the ventral valve near the middle of the front face, 
but forming almost the entire anterior lateral sides before joining the 
opposite valve. Mesial elevation flattened anteriorly, but well defined 
to the middle where it is no longer traceable; a sinus arises anteriorly 
in the middle of the mesial elevation, and becoming well defined ex- 
tends to the beak which is incurved beneath the beak of the ventral 
valve. There are from seven to nine angular plications on the mesial 
elevation, and about the same on either side, making from 21 to 27 
plications, on the specimens examined. Ventral valve somewhat flat- 
tened, most convex in the central part, from which it slopes in all di- 
rections, but flattens out or curves up alittle, at the antero-lateral sides, 
where it is very sharply. geniculated, and unites with the opposite 
valve; toward the front the curvature increases, terminating in an 
abrupt geniculation and extension to meet the other valve in the middle 
of the truncated front. The beak is pointed and eurved over upon 
that of the dorsal valve. The mesial sinus is broad and defined only 
on the anterior half of the valve. The plications are the same in num- 
ber as those that occur on the dorsal valve. 
The surface of both valves is ornamented by fine concentric lamellee 
of growth, which, in crossing the angular plications, make a series of 
zigzag lines, that also ornament the truncated front to the point of 
union of the serrated valves. This is a handsome species readily dis- 
tinguished from all hitherto described. ‘ 
ORTHIS DALYANA, 0. Sp. 
Plate VIL., fig. 8, ventral view ; fig. 8a, dorsal view ; fig. 8b, profile view. 
Shell depressed, suboval in outlite, and length about equal to the 
greatest width, which is at the anterior third. Dorsal valve most con- 
vex above the middle, from which it inclines in all directions to the 
margin, forming a broad, flattened inclination toward the front. Beak 
