NO. 24 PTARMIGANIA STRATA RESSER 55 



than to any other. The glabella is not very well differentiated in 

 front ; in fact, viewed in cross light it merges completely with the 

 preglabellar area. By the light in a longitudinal direction a shallow 

 dorsal furrow may be seen. The eyes are situated far back, almost 

 touching the occipital furrow. The brim is wide and gently concave 

 and has a wide rim faintly indicated chiefly by a change of curvature. 

 This brim contracts only slightly toward the anterior angles, a feature 

 that makes the generic reference doubtful. The surface appears to 

 be smooth. 



Locality 20x. 



Holotype.—U. S.N. M. No. 98553. 



KOCHINA? LIBERTYENSIS, n. sp. 



Plate 12, fig. 6 



A single cranidium in reddish-brown shale represents this species. 

 It is closely associated with a large specimen of Hyolithes and frag- 

 ments of other trilobites. It may not belong to the Ptarmigania fauna 

 but is included because it occurs with material that evidently does 

 belong to the fauna. 



This is a narrow form with a rather strongly tapering glabella, 

 which occupies over two-thirds of the cranidial length. The occipital 

 furrow is clearly impressed, but glabellar furrows are lacking, and 

 there is a slight keel. The brim is simple, swollen in the middle, and 

 depressed at the anterior angles. The anterior furrow swings back 

 from the anterior angles to the anterior dorsal furrow ; consequently 

 the rim widens in the middle to occupy the entire brim width. The 

 eyes are of moderate size and situated about the midpoint of the 

 cranidium. They are elevated as the fixigenes rise rather abruptly 

 from the dorsal furrow and the eye lobes themselves are prominent. 

 The fixigenes at the eyes have about half the glabellar width. 



Locality 59L 



Holotype.—U.S.NM. No. 98554. 



INGLEFIELDIA Poulsen, 1927 

 INGLEFIELDIA IDAHOENSIS, n. sp. 



Plate 12, fig. 9 

 Ingle field ia is distinguished from Kochiella only by its relative 

 narrowness. For this reason this species is put into Inglefieldia. Its 

 features are much like the species of Kochiella here described except 

 that the width across the cranidium at the anterior end of the eye is 

 much reduced by contraction of the fixigenes. 



