JURASSIC FLORA OF DOUGLAS COUNTY, ORGE. 115 



Ctenis orovillensis Fontaine. 



PI. XXVII, Figs. 1-5; PI. XXVIII, Fig. 1. 



1896. Ctenis orovillensis Font.: Am. f urn. Sci., 4th ser.. Vol. II, p. 274 (nomen.). 

 1900. Ctenis orovillensis Font.: Twentieth Ann. Rep. LT. S. Geol. Surv., 1898-99, 

 Pt. II, p. 357, pi. Iviii, fig. 4. 



This splendid plant was found in the Oroville flora. A considerable 

 numloer of specimens were obtained from some of the Oregon localities, 

 which make it possible to add something to the description of its character. 

 The Oregon specimens show the leaflets more completely. The leaves 

 must have been very large, as is indicated by the fragment depicted in 

 Fig. 141, which is the largest found. This is a good deal distorted and 

 mutilated, so that it does not show the exact mode of attachment of 

 the leaflets, as they are toward their bases most imperfect. The figure 

 represents the upper part of a leaf, showing the upper leaflets with 

 their bases very near the axis, but not attached to it. If their 

 attitude is not distorted they must, in this portion of the leaf, have 

 gone off under an acute angle. One of the leaflets in a lower position 

 is nearly entire and will give an idea of the size. Though not entire, it 

 is still 17 cm. long, and near its base is 2 cm. wide. These dimensions 

 are found in what is probably an average leaf, and they indicate a 

 length of 20 cm. In this specimen all the leaflets are distorted in their 

 basal portions. The leaf su])stance appears to have l^een quite thin 

 in proportion to the size of the leaflets. The terminal part of the 

 leaflets was narrowed so as to give the entire leaflet a saber form. The 

 nerves are rather remote and are approximately parallel. They are 

 slender, but sharply defined, and immersed in the leaf substance. 

 They anastomose rather rarely and irregularly, by sending off a 

 branch which unites with an adjacent nerve at a very acute angle. 



PI. XXVII, Fig. 1, gives the most complete specimen found. Fig. 

 2 shows one of the leaflets enlarged. Fig. 3 shows the base of a leaflet, 

 indicating its mode of attachment. This is slightly enlarged in Fig. 4. 

 Fig. 5 gives what seems to have been the upper part of a leaf. It has 

 the basal parts of several leaflets attached to the midrib, but the attach- 

 ment is obscured by distortion. PI. XXVIII, Fig. 1, shows the basal 

 parts of several leaflets, so placed as to indicate a former attachment to 



