58 Shinier and Blodgett — Mi. Taylor Region, New Mexico. 



dip ; this dip increases toward the Nacimiento mountains lying 

 to the east. Thus under the influence of the INTaeimiento moun- 

 tain uplift, these strata have a westerly dip practically to the 

 western limits of the Albuquerque and Jemez sheets, though at 

 this distance from the mountains it is very faint. West of this, 

 the strata take again the slight but dominant northward dip 

 characteristic of the plateau strata as a whole, lying north of the 

 old land of southern New Mexico and Arizona. 



A fossiliferous septaria zone appears again on the southwest- 

 ern corner of the Jemez sheet (locality A). It forms a solid 

 stratum about five feet thick and occurs in the midst of a dark 

 shale which is capped by a thin sandstone stratum. Above 

 this sandstone to the west is seen the steep eastern face of 

 another dark shale capped by a thick, heavy- bedded sandstone. 

 The two following fossils were found in this locality : 



Prionotropis icoolgari (Mantell) 



Placenticeras placenta (Dekay) 



The first species is a good Fort Benton index fossil. The 

 second, though much more characteristic of the Montana, is also 

 rarely found in the Colorado formation. These fossils thus in- 

 dicate an age not earlier than upper Fort Benton. This finds 

 confirmation in the presence of the Fort Pierre species, Astarte 

 evansi, in but slightly higher strata to the northwest, though this 

 would leave but little thickness for the presence of Niobrara 

 between. 



Along the Cabezon road a short distance east of Cabezon 

 peak, a specimen of Astarte evansi (H, and M.) Whitfield was 

 found in thin-bedded sandstone. This species, so far as the 

 writers know, is restricted to the Fort Pierre. 



On the northwestern portion of the Albuquerque sheet at 

 locality B the following section was noted : 



Brownish yellow sandstone ; fossiliferous 10 feet. 



Yellow shales ; fossiliferous in layers 30 feet. 



Black shale ; apparently unfossiliferous ..20 feet. 



The following fossils were collected here : 

 Gryphwa neioberryi Stanton 

 Jnoceramus labiatus (Schlotheim) 

 I. dimidius var. labiatoidesS. and B. 

 ? Yoldia sabelliptica Stanton 

 Anomia prop>atoris White 

 Ostrea bigubris Conrad 

 O. anomioides var. nanus Johnson 

 Cardium pauperculum Meek 

 Turritella whitei var. stantoni S. and B. 

 Lnnatia concinna (H. and M.) 

 Priontropis hyattl Stanton 

 P. woolgari (Mantell) 



