JURASSIC FLORA OF DOUGLAS COUNTY, OREG. 99 



The plant is very abundant at locality No. 7, and is here only inferior 

 in quantity to Pterophyllum rajmahalense. (See p. 102.) It is very 

 abundant at locality No. 4 and is common at locality No. 2. It occurs 

 at localities Nos. 8, 12, and 19. 



Pterophyllum contiguum Schenk. 



PI. XIX, Figs. 7-11. 



1883. Pterophyllum contiguum Schenk: Pflanliche Versteinerimgen aiis Richt- 

 hofen's China, Vol. IV, p. 262, pi. liii, fig. 6. 



The fossil from the Jurassic of China, described by Schenk as Ptero- 

 phyllum contiguum, seems to be the same as a plant that is not rare at some 

 of the Oregon locahties. Schenk seems to have had only one specimen 

 and could not determine its full character. The Oregon specimens are 

 fragments mostly of the middle portions of leaves. The midrib is very 

 strong and rigid in proportion to the size of the leaflets. The leaflets are 

 quite thin in texture. They are linear in form, of the same width from 

 base to apex ; not falcate, but straight. They are very obtuse at their 

 ends and symmetrically rounded off there. They stand at right angles to 

 the rachis. Their form is much hke that of the leaflets of P. mquale, but 

 they are mostly narrower. They vary a good deal in size, being in some 

 cases almost as small as the smallest of the leaflets of P. Nathorsti. The 

 average leaflet is about 2 cm. long and a little more than 2 mm. wide. 

 The smallest forms are somewhat less than 10 mm. long and 2 mm. wide. 

 These are rare. Schenk shows the leaflets as simply touching one another, 

 but in many of the Oregon forms they not only touch but seem to be 

 united, so as to show between two adjacent leaflets what looks like a strong 

 nerve or cord. This may be simply a line of the rock matter squeezed 

 between the adjacent leaflets. The distinguishing character of the plant 

 is the constant close approximation of the leaflets. The nerves are slender, 

 and to be seen require the help of a lens. They are about 5 in number, 

 simple, and parallel to one another and to the margins of the leaflets. 



PI. XIX, Fig. 7, gives a portion of the middle part of a leaf carrying 

 leaflets of the largest size, and Fig. 8 shows a portion of this enlarged. 

 Fig. 9 shows a similar part of a leaf with leaflets of the narrowest kind, and 

 Fig. 10 a portion of the same enlarged. Fig. 11 represents a poorly pre- 

 served portion of a leaf with the narrowest leaflets. 



The plant is most common at locality No. 7, where it is abundant. 

 It is also found at localities Nos. 4 and 19. 



