470 University of Kansas Geological Survey. 



Prionotrojris loevianus White. Plate cm, figs. 3, L 



Prionotropis Icevianus White, 1876, U. S. Geo], and Geog. Surv. West 100th 

 Mer., vol. iv, p. 201, pi. xix, ff. la, b; Stanton, 1892, Bull. U. S. Geol. 

 Surv. No. 106, p. 178, pi. xliii, ff. 3, 4. 



Original description: "Shell moderately large, robust ; vo- 

 lutions four or more, increasing rapidly in size, especially the 

 outer one, so that the umbilicus is rather deep, but yet showing 

 all the volutions, each volution embracing between one-quarter 

 and one-third of the width of each preceding one ; transverse 

 section of outer volution, between the nodes, oval-subquadrate ; 

 surface, upon each side, marked by a row of moderately ele- 

 vated, transversely elongate nodes, situated about one-third of 

 the distance from the umbilicus to the dorsum ; and also by a 

 row of very prominent nodes on each side of the dorsum. Each 

 of these rows consists of the same number of nodes. The dor- 

 sal nodes diverge strongly, but are wholly embraced by each 

 succeeding volution, and do not therefore appear in the umbili- 

 cus. Between these two rows of dorsal nodes, the dorsum is 

 slightly convex, and the outer surface of the shell appears to 

 have been marked by a small median carina. Between these 

 nodes and the umbilicus the sides of the volution are broadly 

 convex. A greater transverse elongation of the lateral nodes 

 than existed in our example would make each continuous with 

 its corresponding dorsal node, which would give to each lateral 

 pair of nodes the character of a rib. It is not improbable that 

 this modification may be found to exist in some examples of 

 the species. Septa complex ; dorsal lobe and part of dorsal 

 saddle unknown ; superior lateral lobe moderately large, but 

 not bifid ; accessory lobes and saddles more or less deeply 

 lobed or notched. Diameter, 140 mm." 



Imperfect specimens of a form which I believe to belong to 

 this species were obtained from the Septaria horizon of the Blue 

 Hills shales on the Saline river north of Hays City. Specimen 

 was imbedded in a hard matrix of one of the Septaria nodules ; 

 therefore its determination was difficult. 



