SECOND CONTRIBUTION TO 

 NOMENCLATURE OF CAMBRIAN TRILOBITES 



By CHARLES ELMER RESSER 



Curator, Division of Invertebrate Paleontology 



U. S. National Museum 



This is the second paper in a series deaHng with nomenclatural 

 changes necessary for certain Cambrian species/ In this contribution 

 several Atlantic Province genera and species are discussed. 



As in the previous paper, only published species are considered 

 because illustrations are not possible. Most of the text is arranged 

 in alphabetical order according to genera, exceptions being made in a 

 few cases where several members of a family are kept together. 



ALBERTELLA Walcott, 1908 



Four species were described by Walcott as belonging to Alhertella, 

 viz, the genotype A. helena, and A. bosworthi, A. levis, and A. pa- 

 cifica. The last named, which comes from Asia, is in reality an inde- 

 terminate fragment and must await the finding of further material 

 before its proper generic assignment can be made. Several new spe- 

 cies of Albertella are in hand beside those recognized below in the disr 

 cussion of the three previously described American species. 



Previous mention has not been made in the literature of the close 

 relationship between Albertella and Ptarmingia. In fact, this is an- 

 other case where the cranidia of the two genera are indistinguishable 

 generically. 



Albertella helena Walcott Genotype 



Albertella helena Walcott (part), Smithsonian Misc. Coll., vol. 53, no. 2, 



p. 19, pi. 2, figs. 1-4, 1908. (Not s — Ptarmingia gordonensis; 6 = A. 



similaris; y-=A. rossensis; 8, g-=A. nitida.) Idem, vol. 67, no. 2, p. 39, 



pi. 7, fig. 4, 1917. 



Middle Cambrian, Gordon ; (loc. 5j) near Scapegoat Mountain, and 

 (loc. 40) Gordon Creek, Powell County, Montana. 



*Resser, Charles Elmer, Nomenclature of some Cambrian trilobites, Smith- 

 sonian Misc. Coll., vol. 93, no. 5, Feb. 14, 1935. 



Smithsonian Miscellaneous Collections, Vol. 95, No. 4 



