56 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 98 



/. idahoensis is based on a single small cranidium. The glabella 

 tapers to a truncated front. Weak glabellar furrows extend directly 

 across the glabella. The fixigenes are nearly the same width through- 

 out, equaling about two-thirds the greatest glabellar width. The eyes 

 are fairly large, situated somewhat behind the midpoint of the glabella. 

 Eye lines weak. Brim wide, with thickened rim slightly wider than 

 preglabellar area. Facial suture does not diverge much anterior to 

 the eye. 



Locality 59L 



Holotype.— U.S.N.M. No. 98555. 



KOCHIELLA Poulsen, 1927 



KOCHIELLA ARENOSA, n . sp. 



Plate 11, figs. 5-9 



This species is evidently fairly abundant, but because it occurs in 

 quartzite only fragments can be obtained. A nearly complete but 

 badly weathered cranidium is in hand. The fragments illustrated are 

 better preserved and show essential features. Libragenes are fairly 

 common, and one pygidium definitely places the species in its genus. 



The glabella is little more than half the length of the head and 

 tapers forward. At its anterior end the dorsal furrow is not clearly 

 impressed, so that the glabella joins the brim, and to do so the anterior 

 angles of the glabella flair somewhat. Brim wide, first convex and 

 then concave. Anterior margin is nearly straight and slightly indented 

 in the middle. The fixigenes at their narrowest point are about as 

 wide as the glabella. The eyes evidently are rather small, situated 

 about the midpoint of the cranidium. Three pairs of glabellar furrows 

 are indicated by fairly sharp depressions, next to the dorsal furrow. 

 Eye lines present. The libragene is of normal form, very simple with 

 a broad concave margin which extends into a long genal spine. The 

 pygidium is of normal composition with a broad axis on which two 

 rings may be seen. The dorsal furrow is shallow and two pleura are 

 differentiated on the lobes. The axis does not stand above the pleural 

 lobes very much, but the lobes are highly convex. The pleural lobes 

 have a wide flairing border, at the rear of which is a deep notch. The 

 pleural lobes are very convex and the pygidium slopes rapidly down- 

 ward from the rear of the axis. 



Locality 59c. 



Holotype and paratypes. — U.S.N.M. Nos. 98556a-d. 



