102 MESOZOIC FLORAS OF UNITED STATES. 



Ptekophtlltjm rajmahalense Morris. 

 PI. XXI, Figs. 1-7. 



1863. Pterophyllum rajmahalense Morr. in Oldham & Morris: Foss. Fl. Gondw. 



Syst., Vol. I, p. 25, pi. xiii, figs. 3-5; pi. xiv; pi. xviii, fig. 2. 

 1876. Pterophyllum Sensinovianum Heer: Fl. Foss. Arct., Vol. IV, Pt. II (Jura-Fl. 



Ostsibiriens) , p. 105, pi. xxiv, fig. 8. 



The plant regarded as Pterophyllum rajviahalense is one of the most 

 important and characteristic of the Oregon Jurassic fossils. Hundreds of 

 specimens were collected at some of the localities. Manj'- of them are 

 well preserved and a larger portion of the leaf is often obtained than is 

 found in the case of most of the plants of the region. Hence all parts 

 of the leaf are well represented. The leaves do not seem to have been 

 long. They are remarkable compact and strong. The largest fragment 

 seen is 18 cm. long. The base and apex are missing. It indicates a leaf, 

 exclusive of the petiole, about 25 cm. long, and this may be taken as about 

 the maximum length. The leaf substance must have l^een very thick and 

 leather-like, for a strong film of coal is left. The leaf is narrowly ellip- 

 tical and widest near the middle, narrowing gradually toward the base and 

 apex. It is terminated by a pair of leaflets that are abruptly diminished 

 in size. The axis or midrib is strong. One is 5 mm. wide, having a petiole 

 of considerable length. This is shown only partially when preserved. 

 The leaflets vary a good deal in size in the same leaf and in different ones. 

 The variation is chiefly in width, the length remaining remarkabl}^ con- 

 stant in similar parts of different leaves. They are always quite wide in 

 proportion to their length. Occasionally one or two aberrant forms, 

 wider oi' narrower, are located in the midst of normal forms. They are 

 usually closely placed. In very rare cases their margins touch. In one 

 case the leaflets appear to be consolidated. They are on different sides 

 of the axis, mostly opposite. They become shorter toward the base and 

 apex. There is a marked tendency to aberrant forms in the basal leaflets. 

 The lowest ones are often much wider than the others, as if two adjacent 

 ones had become consolidated. These then look like leaflets of Nilsonia 

 nippcnensis. They are attached by the entire base to the sides of the 

 axis at a right angle and are perfectly straight, with no tendency to a 

 falcate shape. The}^ are oblong, with parallel margins, and of the same 

 width from base to apex. The tips vary somewhat. In the most com- 



