ART. 4 CAMBRIAN CONCHOSTRACA — ULRICH AND BASSLER 61 



ALUTA DOUVILLEI (Mansay) 



Plate 4, Figure 17 



Bradoria douvillei Mansut, Mem. Service Geol. I'lndo-Chine, vol. 1, 1912, p. 22, 

 pi. 1, fig. 8. 



Judging from the illustration, part of which is reproduced in Plate 

 4, this species belongs to Aluta and is related to species from China 

 with distinct cardinal angles. The crushing of the valves so common 

 in species of Aluta is also shown in Mansuy's figure. 



Occurrence.— Ctunhnan, associated with Redlichia chinensis, be- 

 tween Yi-L^ang and Ko-Pao-Tsouen, eastern Yunnan. 



ALUTA HOLLH (Jones) 



Plate 8, Figure 33 



Beyrichia hollii Jones, Geol. Mag., n. ser., dec. 2, vol. 8, 1881, p. 343, pi. 10, 

 fig. 7. 



This species is apparently based upon a small specimen of Aluta 

 to which genus we now refer it. Further work is necessary before 

 its relationship to the other species of Aluta can be determined. 



Occurrence. — Middle Cambrian (Menevian): St. Davids, Wales. 



ALUTA (?) RIM UL AT A, new species 



Plate 5, Figure 16 



This new species is based upon a complete carapace flattened in 

 the shale, with the result that the surface nodes or ridges are crushed 

 and not very visible. A node on the anterior third and a ridge below 

 it are apparent in other specimens referred here, while still others 

 show the wrinkled appearance often seen in Aluta. The two valves 

 also are so similar that they probably would fit close together. The 

 narrow but conspicuous rim along the free edges of the valves will 

 readil}^ distinguish the species. 



Occurrence. — Middle Cambrian (Ross Lake shale member of 

 Ptarmigan formation): 3 miles souths\est of head of Lake Louise, 

 Alberta. 



Holotype.— Cut. No. 81735 U.S.N.M. 



Genus EREMOS Westergaard 



Eremos (Westergaard Mss.) Moberg and Segerberg, Meddelande Fran Lunds 

 Geologiska Faltklubb, ser. B., No. 2, 1906, p. 75. 



Although based upon a Post-cambrian species this genus has such 

 a resemblance to Aluta that an illustration of the type is included 

 herewith. 



Genotype and only species. — Eremos bryograptorum Westergaard. 



