66 THE OLDER MESOZOIO FLOEA OF VIRGINIA. 



Pterophylluru afEae, Xathorst. 

 Plate XXII, Figs. -2-4. 



Leaf with a strong, rigid midrib; leaflets going off at right angles from the midrib, 

 closely placed, of exactly the same width from base to summit, separate to the base, 

 truncate, or with a summit obliquely cut, so that the upper edge of the leaflet is longer 

 than the lower. Extreme length of the leaflets 3 centimeters; width varying in differ- 

 ent specimens, from 8 to 16 millimeters, normal width 10 millimeters. Nerves very 

 fine, closely placed, simple, and at right angles to the midrib. 



I have identified this plant with the Pterophyllum affine of Nathorst, as 

 described in his "Floran vid Bjuf," and figured on plate xv., figs. 12, 1 3. The 

 only difference is that the Virginia plant attains larger dimensions in some 

 cases, although fig. 4 gives a specimen with leaflets of the same width as 

 those of the Swedish plant, but with a little greater length. Another un- 

 important point is that the Swedish plant has its leaflets wider apart than 

 those of the Virginia fossil. Both plants have the same shape in the leaflets, 

 with the same peculiar oblique or truncated terminations, the same mode of 

 insertion, and the same nervation, which is peculiarly fine and closely placed. 

 The Virginia fossil belongs to the same type of Pterophyllum as the P.propin- 

 quum of Schenk, figured in the " Flora der Grenzsch.," plate xli, fig. 1, and 

 which is given by Feistmantel also on p. 110 of "Pal. Indica," series II, 7, 

 as occurring in the Rajmahal Group of India. It is also not unlike Pterophyl- 

 lum Bajmahalense, Morris, given on plate xiv, of the "Fossil Flora of the 

 Rajmahal Series." Pterophyllum princeps, Oldh. & Morris, given in "Pal. 

 Indica," series II, 7, plate xlvii, seems also to belong to this type of Ptero- 

 phyllum, but these last-mentioned plants are larger than ours. It also 

 resembles closely Newberry's Pterophyllum delicatulum, from Sonora. These 

 plants all have a certain resemblance to Anomozamites. The Virginia fossil, 

 however, presents no evidence that it has any of the leaflets of varying width 

 characterizing Anomozamites. It is no doubt a true Pterophyllum of a char- 

 acteristic Rheetic and Liassic type. 



Formation and locality. — Found only at Midlothian, in material taken 

 out of a deep shaft, the precise horizon not being known; only three or four 

 specimens were found, and on the same slab of sandstone. 



