158 MESOZOIC FLORAS OF UNITED STATES. 



reux's No. 909b. This is given by Lesquereux as Pecopteris denticulata 

 Heer. He gives no description and no figure of it. The imprint shows 

 several imperfect ultimate pinnae carrying a number of mostly mutilated 

 pinnules. The pinnae are detached, but so placed as to show that they 

 were once attached to a common rachis. Enough, however, of the char- 

 acter of this plant is shown to make it most probable that it is identical 

 with Cladophlebis vaccensis, found in the Jurassic (Lower Oolite) flora of 

 Douglas County, Oreg., and described on page 66. Only one specimen 

 of this fossil occurs in the collections. It is represented in PL XXXIX, 

 Fig. 7, and one of the pinnules with its attachment to the rachis is shown 

 in Fig. 8. 



Cladophlebis alata Fontaine. 



PI. XXXIX, Figs. 9-11; PI. XL. 



1888. Aspidium Oerstedi Heer. Lesquereux: Proc. U. S. Nat. Mus., Vol. XI, p. .32 

 in part, quoad Cat. U. S. Nat. Mus. No. 2434, Lesquereux's Nos. 910b, 

 910c, 911b, 912, 916, 917. 



1888. ? Pinus staratscMni Heer. Lesquereux: Proc. U. S. Nat. Mus., Vol. XI, p. 32. 



1889. Cladophlebis alata Font. : Potomac Flora (Monogr. U. S. Geol. Surv., Vol. XV), 



p. 77, pi. xix, figs. 5, 5a. 

 1889. Pecopteris strictinervis Font.: Op. cit., p. 84, pi. xiii, figs.. 6, 6a, 7, 7a, 8, 8a; 

 pi. xix, figs. 9, 9a; pi. xx, figs. 3,*3a; pi. xxii, figs. 13, 13a; pi. clxx, figs. 5, 

 5a, 6, 6a. 



The most common, and perhaps the most characteristic fern of 

 the two collections, is one of those that Lesquereux identified with 

 Aspidium Oerstedi Heer, although it is entirely different from that plant 

 and the others of Woolfe's collection that he placed in that species. 

 Some of the larger rock fragments contain a number of imprints. The 

 amount of material enables one to get a pretty good idea of the character 

 of the fossil. The specimens seem all to belong to parts pretty high up 

 on the pinnae. The most complete specimens show a considerable portion 

 of an antepenultimate pinna, which carries portions of several penul- 

 timate and ultimate pinnae containing a number of pinnules. Whether 

 or not this represents the frond or only a compound pinna can not be 

 determined. It is probably only a pinna. It shows that the frond 

 must have been of considerable dimensions and that the plant was 

 probably arborescent. The rachises are strong and rigid. The primary 

 and secondary rachises of this specimen, given in PL XL, Fig. 1, seem 



