NO. 5 UPPER CAMBRIAN TRII.OBITES RESSER I7 



IRVINGELLA OTTERTAILENSIS, new species 



Plate 2, Figure 49 



One imperfect cranidium is available, but the species is described 

 because of the importance of the fauna. 



The glabella is rather large, with the occipital and first fvuTOws 

 sharply impressed, but the anterior pairs do not show. Convexity 

 cannot be determined because of the partial compression of the fossils 

 from this locality. The faxigenes are more than half the width of the 

 glabella and the eyes are very long, extending from the occipital 

 furrow around the sharply bowed cheeks to the brim. 



"Goodsir" formation ; Moose Creek, Ottertail Range, British 

 Columbia. 



Holotype.— U.S.N. M. No. 108651. 



IRVINGELLA OBLONGA, new species 

 Plate 3, Figures 1-3 



Although this locality has yielded numerous specimens of other 

 Irvingella, only this crandium of a small distinctly marked species 

 was found. 



The glabella is long and subcylindrical, well rounded in front. Its 

 width equals about three-fourths its length. The occipital furrow and 

 the complete rear glabellar furrow are both deep and approximately 

 parallel. The glabella stands completely above the dorsal furrow, and 

 in cross section has practically vertical sides rounding to the slightly 

 flattened top surface. Longitudinally the high convexity is confined 

 largely to the front half so that the anterior lobe overhangs the brim. 

 Brim narrow and slightly upturned. Fixigenes about one-fourth the 

 width of the glabella, retaining about that width throughout their 

 length. The anterior portion decreases to about half the greatest 

 width. The eyes are long and, because of the rather even width of 

 the fixigenes, are not greatly bowed. 



Wilberns formation; (loc. 70) Baldy Mountain, 8 miles northwest 

 of Burnet, Texas. 



Holotypc.—U.S.N.M. No. 108652. 



IRVINGELLA AGRESTIS, new species 



Plate 3, Figures 4-6 



The glabella tapers, owing to the even convergence of the dorsal 

 furrow from the occipital furrow forward. The occipital and first 



