l6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 93 



BILLINGSASPIS, n. gen. 



Several Lower Cambrian species referred with a query to Acro- 

 cephalites constitute a distinct generic group. Since the genotype is a 

 species described by Billings, the hybrid name Billingsaspis seems 

 appropriate. 



Diagnosis. — Cranidium on the whole truncate-conical in shape ; 

 facial suture converging slightly, but because the anterior angles are 

 considerably depressed this feature is accentuated in dorsal view. 

 Glabella tapers considerably ; in limestone specimens three pairs of re- 

 flexed glabellar furrows traceable. Brim consists of a depressed pre- 

 glabellar area and a raised and thickened rim ; some specimens have a 

 small median boss. Eyes small, eye lines present. Fixed cheeks 

 rather wide and rising from the dorsal furrow to the angular palpe- 

 bral lobes. 



Comparisons. — Superficially, Billingsaspis resembles Bolaspis, ex- 

 cept for the depression where the latter has the great boss in the pre- 

 glabellar area. Further study is necessary to show whether this re- 

 semblance indicates genetic relationship. 



Genotype. — Conocephalites vulcanns Billings. 



Range. — Possibly confined to Lower Cambrian. 



Billingsaspis vulcanus (Billings) 



Conocephalites Z'ulcanns Billings, Rep. Geol. Vermont, vol. 2, p. 952, fig. 357, 



1861 ; repeated Geol. Canada, p. 286, fig. 296, 1863 ; original republished. 



Pal. Fossils Canada, vol. i, p. 14, fig. 17, 1865. 

 Ptychoparia vulcanus Walcott, U. S. Geol. Surv. Bull. 30, p. 198, pi. 26, fig. 4 



(not 4a), 1886 U. S. Geol. Surv. loth Ann. Rep., p. 653, pi. 96, fig. 4 



(not 4a :=" Ptychoparia" miser?), 1891. 

 Acrocephalitcs ? vulcanus Walcott, Smithsonian Misc. Coll., vol. 64, no. 3, 



p. 182, pi. 26, fig. 2, 1916. 



Lower Cambrian, Parker; (loc. 25) Parkers quarry, Georgia, and 

 ( loc. 26) Corman farm, east of Highgate Springs, Vermont. 

 Cotypes. — U.S.N.M. no. 15437. 



BLAINIA Walcott, 1916 



Asaphiscus (Blaiuia) Walcott, Smithsonian Misc. Coll., vol. 64, no. 5, p. 393, 

 1916. 



This undoubtedly deserves full generic rank ; in fact, it is doubtful 

 whether it is even closely related to Asaphiscus. 



Genotype. — Asaphiscus (Blainia) grcgarius Walcott. 



Range. — Middle Cambrian. 



Species formerly referred to Blainia: 



B. glabra = Blountia B. paula = Genus undet. 



