Logan.] The Invertebrates, Niobrara Group. 499 



teen mm. The type specimen is attached to an Ostrea congesta 

 by the extremity of its peduncle. It was discovered by Pro- 

 fessor Haworth, and placed provisionally in the genus Pollicipes 

 by Professor Williston in the work cited. Its horizon is the 

 yellow chalk from the vicinity of Gove City, in Gove county. 



Stramentum tabulatum Logan. 



Str amentum tabulatum Logan, 1897, Kans. Univ. Quart., vol. vi, No. 4, Oct., 

 series A, p. 189. 



Description : Capitulum composed of eight plates, viz. : Terga 

 (2), scuta (2), lateralia (4) ; height, five mm. ; breadth, seven 

 mm. The plates are flat and marked by lines, and the whole 

 capitulum is short and pointed. Terga triangular, the longest 

 side of the triangle adjoining the carino-lateral, the shortest 

 side adjacent the superior lateral ; breadth at base, two mm. ; 

 height, five mm. Scuta small, but one-half the size of the terga ; 

 triangular, almost equilateral. Carino-lateral long, moderately 

 narrow, triangular, the most acute angle at the apex ; height 

 and breadth about the same as those of the terga. Superior 

 laterals small, in the form of an isosceles triangle, and of about 

 the same size of the scuta. Peduncle short, rounded, composed 

 of six, or possibly seven, rows of plates, with about sixteen 

 plates in each row ; plates less than one mm. in width, their 

 length more than two mm. ; turned downward at the ends and 

 overlapping in rows. 



Type specimen was collected by Mr. H. T. Martin from the 

 Upper Niobrara chalk of the Smoky Hill river. 



Squama. 



Squama Logan, 1897, Kans. Univ. Quart., vi, 187. 



Description : Capitulum composed of from nine to twelve 

 plates of medium size and subtriangular ; peduncle short, com- 

 posed of seven rows of plates, tapering gradually to near the 

 extremity, and ending in a rapidly, almost abruptly, diminish- 

 ing reflex area of smaller plates ; form adhering to Inoceramus 

 by its entire length. 



