50G MESOZOIC FLOKAS OF UNITED .STATES. 



Leptostkoiu.s LoxGiroLirs Fontaine. 



PI. ex. Ficr. 11. 



1SS9. Lepfosfrohus Jongifolius Font.: Potomac Flora CMonogr. U. S. Geol. Surv., 

 Vol. XV), p. 228, pi. ci, iig.s. 2, :',; pi. cii, iigs. 1-4; pi. ciii, figs. (1, (ia-do. 

 7, S, 8a. 9-12: pi. civ, % 6. 



In the collection occurs one .specimen of Lcptostrohus longii'olius 

 which shows leaves attached to a portion of a stem. These show a 

 peculiar broadening at the base, where attached, which is probably 

 due to distortion from pressure. PL CX, Fio;. 11, is given to show this. 

 The impression occurs on the rock specimen, No. 8431, with other species. 



Onychiopsis psilotoides (Stokes & Webb) Ward." 

 PI. CXI, Fig. 4. 



This plant is of much importance in this collection. PI. CXI, 

 Fig. 4, gives the best of the three specimens found. It is a portion 

 of a penultimate pinna with a number of ultimate ones, carrying well- 

 characterized pinnules. The imprints are all on a single slalj in coun- 

 terparts, the part bearing the one figured being No. 8428 and the 

 counterpart No. 8430 of the INIaryland Geological Survey. 



This fern is more characteristic of the Rappahannock than of the 

 Aquia Creek horizon. 



Sas.safras bieobatum Fontaine.? 



PI. CXI, Fig. 5. 



1889. Sassafras bilobatum Font.: Potomac Flora (Monogr. U. S. Geol. Surv., Vol. 

 XV), p. 290, pi. clvi, fig. 12; pi. clxiv, fig. 4. 



There is in the collection a fragment of a leaf of considerable size 

 which is of problematic character but which in some points resembles 

 Sassafras bilobatum from the Aquia Creek horizon of the Virginia Lower 

 Potomac. It is, however, too poorly preserved to permit its true char- 

 acter to be made out. It is most like the form given in Monograph XV, 

 pi. cbciv, fig. 4, but the fragment indicates a leaf larger than the one 



«For synonymy of this species sec pp. 155-156.. 



