42 SMIIIISOXIAX MISCEI-LANEOUS COLLECTION'S VOL. IO3 



PLATYCOLPUS SINCLAIRENSIS, new species 

 Plate 6, Figures 32-36 



Though there are in hand about lo pygidia and about an equal 

 number of libragenes, only one fragmentary cranidium, not altogether 

 typical, has been found in the collection. 



The libragene is almost flat in its rear portion but increases greatly 

 in convexity forward, indicating that the cranidium must have been 

 considerably arched longitudinally. The ocular platform is approxi- 

 mately a quarter circle and is surrounded by a wide, thickened, heavily 

 striated border, with the striations turning toward the margin as the 

 genal angle is approached. 



The pygidium is rather convex, with the axis standing well above 

 the pleural lobes, but the dorsal furrow is merely a change in slope. 

 Several pleural furrows are visible on exfoliated specimens. The axis 

 is rather long, extending beyond the midpoint of the pygidium. 



Sabine formation; (loc. i6t) Sinclair Canyon, Brisco Range, 

 British Columbia. 



Holotypc. — U.S.X.M. No. 108697a; paratypes Nos. 108697b, c. 



ENONTIOURA, new genus 



Although up to the present time only the holotype pygidium has 

 been discovered, it is given a new generic name because it represents 

 such a strange form. On the same piece of rock is a rounded 

 cranidium similar to that of Caniaraspis but it is not well enough 

 preserved to warrant description. 



The specimen assumed to be a pygidium is characterized by a very 

 large axis, which occupies most of its area. At the front of the wide 

 axis is a half segment which looks more like a rim than the usual 

 segmental division. Shallow dorsal furrows separate narrow pleural 

 lobes, the dorsal furrow continuing very faintly around the rear of 

 the axis. Beginnning at the anterior angles a thickened, slightly 

 upturned rim borders the outer edge of the pygidium. Aside from 

 the peculiarity of shape and convexity, a very unusual feature is found 

 in the striations which transverse the entire specimen from side to 

 side, crossing both the axis and the pleural lobes. It is this feature 

 which has several times raised the question as to whether this specimen 

 is actually a trilobite pygidium or some oddly formed hypostoma, or 

 even an undescribed crustacean. In view of these conditions, a descrip- 

 tion of this specimen is presented primarily to call it to the attention 

 of geologists with the hope that its real position may be discovered. 



Name. — eroji'Ttos = contrary ; ovpa = ta.\\. 



Genotype. — E. typicalis, new species. 



