350 Systematic Paleontology 



uncovered in the quarry at Fredericksburg, and to have had the appear- 

 ance and dimensions as shown in Professor Fontaine's Fig. 2, cited above. 

 This was unfortunately completely broken up in getting it out, the best 

 of the remaining fragments being that shown in fig. 1 of the present 

 work. This shows the upper surface of the frond and emphasizes its coria- 

 ceous texture. As previously stated, the pairs of veins appear as a single 

 flat vein in this specimen. Fig. 2 of the present work shows an impres- 

 sion of the under surface of a frond of somewhat smaller size and brings 

 out clearly the slender, double veins of this species. 



This same form has been recorded (loc. cit.) from the Horsetown 

 beds in California but the identification is based on rather uncertain 

 material which, however, may well be identical with the Virginia form. 



The fragments from Virginia which were described by Professor 

 Fontaine as Podozamites grandifolius are obviously referable to this 

 species with which they are identical in size, texture, and in the peculiar 

 double veins. They represent somewhat distorted fragments of 

 detached pinnules. The supposed contracted base shown in the fore- 

 going author's fig. 5 is entirely fanciful. Other remains subsequently 

 referred to this species ^ are of doubtful value. 



Occurrence. — Patuxent FoRMATioisr. Fredericksburg, Potomac Eun, 

 Virginia. 



Collection. — U. S. National Museum. 



Genus CTENOPTERIS Saporta 

 [Pal. Franc, t. i, 1873, p. 351 (Brongn. MSS.)] 



This genus was established by Saporta in 1873 with the Filicites 

 cycadea of Brongniart,^ a Jurassic species, as the type. He charac- 

 terized it as follows : 



" Frons pinnata vel bi-tripinnata, pinnae elongato-lineares pinnatiparti- 

 tae basi exappendiculatae, pinnulae basi tota adnatae decurrentes inter 

 se liberae versus apicem pinnarum plus minusve confluentes, brevi omnes 



' Fontaine, Mon. U. S. Geol. Surv., vol. xlviii, 1906, p. 167, pi. xliv, fig. 1. 

 ^ Brongn., Hist., Veget. Foss., 1828, p. 387, pi. cxxix, figs. 2, 3. 



