JURASSIC FLORA OF DOUGLAS COUNTY, OREG. 101 



They are attached by the entire base to the sides of the axis of the leaf, 

 nearly or quite at a right angle. The width is the same from the base to 

 near the tip, where they are usually slightly narrowed, so that they have . 

 elliptic terminations. They are generally not very closely placed. They 

 vary somewhat for different leaves in length and width, and in the same 

 leaf become shorter toward the base and probably toward the end. No 

 ends were seen. Taking the leaflets from near the middle part of the leaf 

 as the normal ones for description, the average length may be put at 25 

 mm. and the average width at 3-4 mm. As extreme variations we may 

 have in similar parts leaflets 35 mm. long and 6 mm. wide for the maximum 

 size and 10 mm. long and 3 mm. wide for the minimum. The variation is 

 mainly in length. Nathorst in his diagnosis of the species says that the 

 nerves of the leaflets are mostly dichotomous at base. In the Oregon 

 specimens they may be dichotomous at or near their bases, but they are 

 mostly single, especially in the smaller forms. They are parallel to one 

 another and slender, not being easily seen without the help of a lens. 

 They do not vary much in strength from their base to their ends, and are 

 10-12 in number. 



PI. XX, Fig. 1, gives a portion of what seems to have been the middle 

 part of a leaf, with leaflets of maximum size. The terminations of most 

 of them are not shown. Fig. 2 shows a fragment of a similar part of a 

 leaf carrying narrower leaflets, but of a length equal to that of those given 

 in Fig. 1. This large form is quite common at locality No. 2 and is mostly 

 missing elsewhere. It is strikingly hke P. Jcegeri Brongn. of the Trias. 

 Fig. 3 is an enlargement of two of the leaflets of Fig. 2. Fig. 4 shows the 

 middle part of a smaller form with leaflets still rather wider than the 

 average. Fig. 5 gives a fragment of a leaf with leaflets that may be taken 

 as average ones. Fig. 6 shows the middle pai't of another leaf with 

 average-size leaflets. Fig. 7 shows the upper part of one of the leaves 

 with the smallest leaflets. 



The plant is most common at locality No. 7, where the average and 

 smaller forms are found. The larger forms are abundant at locality No. 2. 

 to the exclusion of others. It occurs also at locahties Nos. 1, 4, and 19. 



