6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 97 



ACROTRETA Kutorga, 1847 

 ACROTRETA NITENS, n. sp. 



Plate I, figs. 3-5 



The generic reference is not certain, for this species differs from all 

 descrihed forms of Acrotreta. Recently, similarly constructed species 

 have been found in both Lower and Middle Cambrian collections. The 

 illustrations present clearly the characteristics of the species. 



Locality 37n. 



Cotypcs. — U.S.N.M. no. 95024. 



AGNOSTUS Brongniart, 1822 

 AGNOSTUS BONNERENSIS, n. sp. 



Plate I, figs. 16, 17 



This agnostid is a typical form of the Cordilleran Middle Cambrian. 

 The characteristic features place it between A. nwntis Matthew of the 

 Stephen formation and A. interstrictus White from the Wheeler shale 

 of Utah, A. bonnerensis has also been compared with the undescribed 

 species in the Spence shale fauna, from which it differs in possessing 

 axial furrows on the pygidium. 



Locality 37n. 



Holotypc and parafypcs. — U.S.N.M. no. 95025. 



PAGETIA Walcott, 1916 

 PAGETIA FOSSULA, n. sp. 



Plate I, figs. 8- 1 1 



P. fossiila is similar to P. clytia from the Spence shale, but dift'ers 

 in having a median furrow like P. hootes. The pygidium has short 

 axial spines. 



Locality 37n. 



Cotypcs. — U.S.N.M. no. 95026. 



ALBERTELLA Walcott, 1908 

 ALBERTELLA SAMPSONI, n. sp. 



Plate I, figs. 24-26 



The glabella of this species is long and is not expanded much in 

 front. The pygidium is wide, much like A. Helena and has a rather 

 wide concave border, with a nearly straight posterior margin. The 

 spines diverge more than average. 



Locality 37m. 



Holotype and paratypes. — U.S.N.M. no. 95027. 



