242 MESOZOIC FLORAS OF UNITED STATES. 



to l:)elong to this species. The specimens on which the former determi- 

 nation was based are represented in PI. LXVI, Figs. 9, 10, and were 

 collected in the Horsetown beds near Riddles, Oreg. 



Family ODONTOPTEPJDE^. 



Genus CTENOPTEEIS Brongniart. 



Ctenopteris integrifolia Fontaine. ? 



PL LXYI, Figs. 12, 13. 



1889. Ctenopteris integrifolia Font.: Potomac Flora (Monogr. U. S. Geol. Surv., 

 Vol. XV), p. 158, pi. Ixii, fig. 2; pi. Ixv, figs. 3, 3a. 



Among the fossils of the Shasta formation two imprints were found 

 that have a problematic nature. They consist of small fragments of 

 leaves that show only the bases of segments, which have the appearance 

 of a cycad in some points. Although the fragments are small, the)^ are 

 very distinct. The segments are 4 mm. in width, and as the basal 

 portions only are shown their length is not disclosed. They are attached 

 b}^ their entire base to the side of the midrib, are separate to the base, 

 and slightly decurrent on the lower side. The nerves are slender but 

 distinct. They go off obliquely from the midrib in a parallel .manner 

 throughout the entire width of the segment, and in this respect resemble 

 Ctenophyllum and Dioonites. But, unlike these genera, the nerves are 

 forked one or more times at varying distances from their insertion on 

 the midrib. The amount of material is entirely too small to permit 

 a positive determination of this plant, but from its resemblance to the 

 peculiar genus Ctenopteris found in the Lower Potomac of Virginia, and 

 more especially C. integrifolia Font., I have referred the plant to that 

 species. This, however, can be done only with doubt and for the sake 

 of reference. It is to be noted that the Virginia plant was not fully 

 made out, owing to the insufficiencj^ of the material. 



PI. LXVI, Fig. 12, gives a small l^it of the leaf, with the bases of 

 two segments, and Fig. 13 a portion enlarged, to show nervation. 



This plant occurs at localities Nos. 1 and 4. 



