NO. 4 CAMBRIAN TRILOBITES, 2D CONTRIBUTION RESSER I5 



It will be observed that besides the genotype C. stilzeri, several 

 species remain in the genus. These include C. ? humerosa Salter from 

 England and four species from Bohemia, C. granulata, C. latifrons, 

 C. mutica, and C. punctata, differentiated by Corda from C. sulseri 

 v^^ith which they were subsequently placed by Barrande ; they seem 

 however, to be good species. 



C. lantenoisi Mansuy from Tonkin, C. frangtengetuis Reed from 

 Kashmir, and C. ulrichi Resser and Endo from Manchukuo must be 

 referred to Bailiella, if they do not constitute a new genus. 



BAILIELLA Matthew, 1885 



Bailiella Matthew, Trans. Roy. Soc. Canada, vol. 2, sec. 4, p. 103, 1885. 

 Erinnys Salter, Quart. Journ. Geol. Soc. London, vol. 21, p. 746, 1865. 

 Erinnys Gronwall, Danmarks Geol. Unders., vol. 2, no. 13, pp. 84, 213, 1902. 

 Salteria Walcott, U. S. Geol. Surv. Bull. 10, p. 31, 1884. 



Salter recognized the distinctness of these trilobites from Cono- 

 coryphe, but the name Erinnys, which he assigned to them, proved to 

 be preoccupied ; the same situation developed respecting Walcott's 

 substitute Salteria. Matthew proposed Bailiella as a subgenus of 

 Conocoryphe without recognizing the relationship between B. haileyi 

 and B. venulosa Salter. Moreover, because Miller named B. haileyi as 

 the genotype, the genus must rest on that species. 



Diagnosis. — Cephalon semicircular ; glabella well defined, tapered, 

 with glabellar furrows. Eyes lacking. Fixed cheeks large, apparently 

 extending to the lateral margins. Marginal furrow extends entirely 

 around the cephalon. Rim generally of even width but sometimes 

 slightly expanded in the middle. Preglabellar area always present and 

 exceeds that of Conocoryphe. 



Thorax and pygidium typical of the family. 



Surface rarely smooth but usually pustulose or lined or both. Usu- 

 ally a ridge or vein extends outward across the cheeks from the dorsal 

 furrow, arising near the front of the glabella. This ridge occupies the 

 position of, and resembles, an eye line, but in some species it is more 

 like a vein branching as it advances. Anterior to this ridge the sys- 

 tem of surface ornamentation characterizing the species gives way 

 frequently to lines or veins. 



Comparisons. — Compared with Conocoryphe, Bailiella is readily 

 distinguished by its wider preglabellar area and the absence of fur- 

 rows across it. Its separation from Bailiaspis is less sharp because 

 some species of Bailiella develop a slight thickening of the rim in the 

 middle of the head. 



Genotype. — Conocephalites haileyi Hartt. 



Range. — Middle Cambrian of the Atlantic Province. 



