C. D. Walcott — Cambrian Fossils from Mt. Stephens. 165 



1886,* and the second species, Embolimus rotundatus, as 

 Bathyicriscus Howelli. \ 



When studying the Georgia fauna, in 1885, I found that the 

 genus Olenoides was probably the same as the genus Dorypyge 

 of Dames.;}; Wishing more material for comparison I left all 

 the species under the genus Olenoides. A large, fine species 

 of the genus Olenoides was collected in the Cambrian shales of 

 Northern Alabama, in 1886, which proved conclusively that 

 Dorypyge was founded on a species congeneric with the type 

 of Olenoides. I then recognized that the species Olenoides 

 typicalis, 0. spinosus, 0. levis and 0. flagricaudatus formed 

 a distinct generic group, which I was having drawings prepared 

 to illustrate when Dr. Rominger' s paper appeared. As the 

 generic name proposed by him is preoccupied, I now propose 

 the name Zacanthoides, including in it : Z. typicalis, Z. spino- 

 sus, Z. levis and Z. flagricaudatus. The species remaining 

 under Olenoides are 0. Nevadensis, 0. Marcoui, 0. quadri- 

 ceps and 0. Wasatchensis. S 



By a comparison of specimens I' found Xk&\#Einbolimus 

 spinosa Rom.= Zacanthoides spinosus Walcott, Embolimus 

 roUcndnta Rom.= B 'athyicriscus Howelli Walcott, Ogygia ser- 

 rata= Olenoides Nevadensis Meek ; and that Conocephalites 

 Cordillera? Rom. = Ptychoparia Cordilleras Rom. (sp.), and 

 Ogygia ff Klotzi Rom. are new to the previously known Cam- 

 brian fauna.^ 



Zacanthmdes spinosus Walcott, 1886= Embolimus spinosa 

 Rominger, 1887.— This is a strongly marked species and occurs 

 at Pioche and Eureka, Nevada, and in the collections from Mt. 

 Stephens. 



Bathyuriscus Howelli Walcott, 1886§= Embolimus rotun- 

 datus Rominger, 1887. — In the type figure of this species one 

 segment has been forced beneath the head, a fact that was 

 overlooked in the original specimen. A comparison of speci- 

 mens from Mt. Stephens with the type from Pioche, Nevada, 

 shows them to be specifically identical. 



Olenoides Nevadensis Meek— Ogygia serrata Rominger. — 

 This fine species is the type of the genus Olenoides ; and a \y 

 comparison of the specimens from Mt. Stephens with the type 

 specimens leaves no doubt in my mind as to their specific 

 identity. 



Ptychoparia Cordillerm Rominger. — A specimen of this 

 species, 23 mm in length, has nineteen segments- in the thorax 

 and in this respect is similar to Ptychoparia Piochensis Wal- 

 cott, from the same horizon, at Pioche, Nevada. The head, 



* U. S. Geol. Survey, Bull. Xo. 30, p. 184, Plate XXV. fig. 6. 



f Loc. cit., p. 216, Plate XXX, figs. 2, 2a. 



\ Loc. cit.. p. 221. 



§ U. S. Geol. Survey, Bull Xo. 30, Plate XXX, fig. 2. 



