62 Shinier and Blodgett — Mt. Taylor Region, New Mexico. 



The specimens were found along the road fifteen miles south- 

 east of Cabezon on the northwestern part of the Albuquerque 

 sheet. 



The type specimen is now in the collection of the Boston 

 Society of Natural History ; catalogue number 13,342. 



Inoceramus dimidius var. labiatoides nov. var. 



Pteria lin gulf or mis E. and S. 

 (TJ. S. G. S. Terr, ix, p. 32.) 



A somewhat imperfect right valve of a young specimen. 

 As far as can be seen it agrees with the original description in 

 shape of shell, relative length of hinge line, position and obli- 

 quity of beaks, and, as far as preserved, the surface ornamen- 

 tation . 



Locality and position, — A single specimen was found in a 

 yellowish, rather heavy-bedded sandstone at the foot of J^eck 

 3, on its northwestern side. The strata are of uppermost Fort 

 Benton or possibly of Niobrara age. 



Trigonarca depressa White. 



(U. S. G. S. Bull. 106, p. 93.) 



The specimens agree closely with the original description in 

 size and shape of shell, and in ornamentation, though the 

 broad, flat, radiating costse are faintly visible only upon the 

 younger shells. The prominent, radiating, raised line on the 

 flattened triangular space posterior to the umbonal ridge is 

 wanting. A ridge covered with radiating vascular grooves 

 extends around the interior of the valve some distance from 

 its margin ; this shows rather conspicuously on the internal 

 mold. 



Locality and position, — This species is present in very great 

 numbers in the heavy-bedded brownish sandstone at the north- 

 western foot of Neck 3 in strata of upper Fort Benton or 

 possibly of Niobrara age. In layers it occurs so abundantly 

 as to make up the rock mass. The type of the species was 

 found some fifteen miles farther down the Rio Puerco valley. 

 It has also been found by Herrick and Johnson southeast of 

 the Prieta mesa. 



