12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 95 



Compared with B. lata this is a narrow form and finer also in its 

 other features. 



Occurrence same as preceding. 

 Cotypes. — U.S.N.M. no. T5421C, d. 



CEDARIA Walcott, 1924 



Cedaria burnetensis (Walcott) 



Ptychoparia burnclcnsis Walcott, Proc. U. S. Nat. Mus., vol. 13, p. 272, pi. 

 21, fig. I, 1890. 



Two cranidia and a pygidium occur on the single small block con- 

 taining the holotype. 



Upper Cambrian, Hickory; (loc. Gyy:) Tatur Hill, Burnet County, 

 Texas. 



Holotype.— {J. S.'^M. no. 23854. 



CLAVASPIDELLA Poulsen, 1927 



Clavaspidella sylla (Walcott) 



Bathyuriscus (Polielfa) sylla Walcott, Smithsonian Misc. Coll., vol. 64, no. 5, 



p. 354, pi. 48, figs. 3-3f, 1916. 

 Clavaspidella sylla Resser, Smithsonian Misc. Coll., vol. 93, no. 5, p. 21, 1935. 



The references to this and the following species were mixed in typ- 

 ing the 1935 report. 



Middle Cambrian, Chetang; (loc. 61 o) Coleman Glacier Creek, 7 

 miles northeast of Robson Peak, Alberta. 



Lcctotype. — U.S.N.M. no. 62645 ; paratypes, nos. 62646-62651. 



Clavaspidella probus (Walcott) 



Bathyuriscus (Poliella) probus Walcott, Smithsonian Misc. Coll., vol. 64, 

 no. 5, p. 354, pi. 65, figs. 2, 2a, 1916. 



It will be noted that this is the youngest species referred to the 

 genus. Moreover, in several features it is no longer fully typical, and 

 for this reason some question concerning its generic afifinities must 

 remain. 



Middle Cambrian, Marjum; (loc. no) about 4 miles southeast of 

 Antelope Springs, House Range, Utah. 



Cotypes.— U.S.N.M. no. 62837, 62838. 



CONOCORYPHIDAE Angelin, 1878 



The trilobite species referred to this family need thorough revision, 

 but to do the task properly would require a monographic study of 

 several years duration. However, a hasty review of the literature per- 

 mits a tentative revision of the group which seems to warrant publica- 



