238 H. W. SHIMEB SPIRlFEKOlDS OF LAKE MINNEWANKA SECTIOK 



or more plications and the fold is from the beginning divided into two 

 plications, which subsequently bifurcate; the fold thus toward the an- 

 terior margin bears usually four plications, sometimes six, and all of 

 nearly equal size. 



As in the Canadian region, so in the Yellowstone Park, S. centronatus 

 is by far the most abundant and universal form. 



Eange. — It has been observed in a wide geographical range, having 

 been described from the Waverly of Ohio, Iowa (Kinderhook), Black 

 Hills. Wyoming, Montana. Wasatch Eange of Utah, and Xevada. 



Spirifer striates (Martin) 



Our specimens agree with this species in their regularly arched cardi- 

 nal area of pedicle valve, the character of sinus and fold, and in the 

 number of plications (on sides of shell about 10 in one-half inch one 

 inch from beak). They vary in length of hinge line from 35 to 70 milli- 

 meters, but the European specimens of this species vary likewise greatly 

 in size. 



Ours agree with Hall and Whitfield's Utah specimens apparently in 

 all respects except in the low cardinal area of their forms: but since 

 theirs were crushed this may be due to that fact. 



Horizon. — Mountain limestone of Europe, Mississippian of Utah. Xe- 

 vada, Xew Mexico ; also reported from the Pennsylvanian of Utah and 

 Xew Mexico. At Lake Minnewanka it is common in the upper portion 

 of the Lower Banff shale. 



Spirifer striatus madisonensis Girty 



A single brachial valve agrees with this variety in its size, its coarse 

 plications, and the character of the median fold. 



Horizon. — Madison limestone of Yellowstone Xational Park; lowest 

 portion of Upper Banff limestone, Lake Minnewanka. 



Amboccelia umbonata (Conrad) 



Our specimens agree in every respect with the descriptions and figures 

 given by Hall. 7 



Eange. — Upper Devonian of Xew York and Pennsylvania. Waverly 

 (Bedford shale) of Ohio. At Lake Minnewanka it is common in the 

 lower portion of the Lower Banff shale. 



T Paleontology of Xew York. vol. 4. pp. 259. 260. pi. 44. 



