wAi.corr.l PALEONTOLOGY — TEXAS AND ARIZONA. 235 



Conocophalites depressus, p. 219. 



billingsi, p. 220. 

 Dikelocephalus roemeri, p. 220. 

 Discina microscopica, p. 221. 



and he mentions Camerella sp. ?, and Capulus sp. ? (p. 221). 1 He cor- 

 relates this fauna with that provisionally designated as u being very 

 analogous to the Potsdam of Iowa, Wisconsin, and Minnesota," 2 and 

 refers it to the Potsdam sandstone. 



In the collections obtained by Mr. C. D. Walcott in his reconnais- 

 sance of the central area of Texas the following species have been 

 identified : 



Eocystitessp. ? Ptychoparia occidens, Walcott. 



Lingnla acuminata, Conrad. affiuis, Walcott. 



perattenuata, Whitf. burnetensis, Walcott. 



Obolella polita, Hall. llauoensis, Walcott. 



Triplesia priniordialis, Whitf. ? metra, Walcott. 



Orthis coloradoensis, Shumard. pero, Walcott. 



remnichia, Wiuchell. ? urania, Walcott. 



Platyceras texanum, Walcott. similis, Walcott. 



Bellerophon antiquatns, Whitf. patersoni, Hall. 



Dikelocephalus iniuuesotcnsis, perseus var., Hall. 



Owen (?). wisconsensis, Owen. 



belli, Billings. Agraulos convexus, Whitf. 



Ptychaspis granulosa, Owen. Agraulos ? sp. ? 

 Chariocephalustumifrons, H. & W. Ilkenurus dia, Walcott. 



This fauna will be illustrated in connection with a review of the Up- 

 per Cambrian fauna of North America now in course of preparation. 



Id 1890 Mr. Walcott 3 described the following new species from Up- 

 per Cambriau strata of Burnet and Llano Counties : 



Platyceras texanum, p. 2G8. 

 Ptychoparia burnetensis, p. 272. 



llanoensis, p. 272. 



t metra, p. 273. 



pero, p. 274. 



? urania, p. 274. 

 Illaenurus ? dia., p. 277. 



ARIZONA. 



The paleontologic work on the Cambrian fauna found in Arizona has, 

 thus far, been confined to the identification of the species discovered 

 in the Ton to formation of the Grand Canon. A preliminary study of 

 the fauna has been made and drawings prepared of the species, but up 

 to the present time nothing has been published in relation to them. 



1 The Primordial zone of Texas, with descriptions of new fossils. Am. Jour. Sci. 2d ser., vol. 32, 

 186 J, pp. 213-221. 



2 Op. cit., pp. 217, 218. 



8 Description of now forms of Upper Cambrian fossils. U. S. Nat. Mus. Proc, vol. 13, 1890, pp. 2C7-279. 



