120 KANSAS UNIVERSITY QUARTERLY. 



of the joints are crenulate and the articulating surfaces are ornamented 

 by five petalloidal areas radiating from a central canal. The nodal 

 joints are ornamented with rounded, tapering cirri, which are composed 

 of small, disk-like joints. No complete specimens of the calyx were 

 obtained, but from one or two incomplete ones I judge the size is 

 small. The free arms are several inches in length. 



Dimensions of joints: Length, 1 mm.; diameter, 2 to 3 mm. 



Geological horizon : Fragments occur somewhat abundantly in No. 

 13, but more abundantly in No. 15. 



Locality : Freeze-out Hills, Wyoming ; also Black Hills, South 

 Dakota. 



Remarks: This species seems closely allied to Pentacrinus suh- 

 an.giilaris Mill., from the Upper Lias of northern Eurasia. When the 

 calices are compared, greater differences may be noted than are re- 

 vealed by the stems. 



Pleuvoutif(t snhcouipressa Meek. Plate XXVI, figs. 4, 7, 8. 



Shell medium size, convex, greatest convexity in the anterior re- 

 gion, form triangularly wedge-shaped. The beaks are prominent, 

 extending above the hinge line and slightly recurved. They are 

 somewhat flattened anteriorly. The hinge is short and straight. The 

 posterior border is nearly straight ; straight in some specimens, and 

 slightly curved in others, in which case the convexity of the border 

 is greatest near the median line. The basal margin has a curved out- 

 line, the anterior basal portion of which is truncated. 



The dorsal margin is short and rounds off gradually into the two 

 adjacent margins. The surface of the shell is ornamented with con- 

 centric ridges, which are somewhat irregular in degree of prominence 

 and form nearly parallel lines on the j)osterior portion of the shell. 

 In the majority of specimens the ridges are more prominent on the 

 posterior and ventral portions of the shell. 



Dimensions : Length, 40 mm. ; width, 25 mm. ; height, 8 mm. 



Geological horizon : This species occurs in the arenaceous nodules 



of No. 13 of the section. The same stratum also furnishes Astarte 



packardi, Pinna kingi, Goniomyamontanaensis, Belemnitesdensus, 

 etc. 



Locality : Freeze-out Hills, Wyoming ; also reported from Utah, 

 Montana, Idaho, Colorado, and Dakota. 



Pleuromya stihcompressa is found also in the Queen Charlotte 



fauna of the Pacific, and assists in its correlation with the fauna of 



interior. 



Ostfefi strhjilccaht White. 



This species is so variable in form that a number of forms have 



been drawn and described by the author in order to bring out these 



differences. 



