66 Shinier and Blodgett — Jit. Taylor Region, New Mexico. 



P. ? rolundatum Johnson. 



(Geol. Cerrillos Hills, p. 135.) 



Our specimens agree quite closely with the type description. 



Locality and position, — They were found in a septarium.in 

 the midst of a dark shaly sandstone a mile southwest of Casa 

 Salazar at Neck 14. Age of strata is Fort Benton. 



? Prionocyclus Wyoming ensis Meek. 

 (Bull. U. S. G. S. 106, p. 171.) 



External mold of a part of a volution. May be referred to 

 this species. 



Locality and position, — It was found in a brownish yellow 

 sandstone at the foot of Neck 14, one mile southwest of Casa 

 Salazar. The strata are Fort Benton . 



Prionotropis hyatti Stanton. 



(Bull. U. S. G. S. 106, p. 176.) 



A young specimen of this species measures f inch in 

 diameter and consists of four whorls. The costae are too 

 unequal for the form to be the young of P. woolgari and the 

 keel is too prominent. This species was found by Stanton ' 

 in the Pugnellus sandstone (upper Fort Benton) of Colorado. 

 The genus, according to him, is not found above the Colorado 

 formation. 



Locality and position,— Two young specimens of this species 

 were found at locality B on the northwestern corner of the 

 Albuquerque sheet, in a dark shaly sandstone of uppermost 

 Fort Benton age. 



P. woolgari Mantell. 



(Bull. U. S. G. S. 106, p, 174.) 



Three specimens were found with diameter 7, 5, and |- inches 

 respectively. The largest specimen agrees with Meek's descrip- 

 tion in general size and shape. The outer whorl, however, 

 shows a flattening and broadening of costse unlike the wing- 

 like appearance noted in his description, and is more quad- 

 rangular in outline. The specimen of medium size resembles 

 the first and second whorls of the larger except that the whole 

 is flatter, with larger umbilicus and less prominent nodes and 

 costse. This larger specimen seems to show gerontic charac- 

 teristics and to be intermediate in stage between the type 

 specimen and the gerontic individual described by Johnson in 

 the Geology of the Cerrillos Hills, page 142. 



The smallest specimen of this species is a little over a half 

 inch in diameter, and is composed of three whorls. It has 

 developed no nodes on the simple ribs, while the keel is low 

 with a well developed flattening of the shell on each side of it. 



