754 GEOLOGY OF THE YELLOWSTONE NATIONAL PAEK. 



entire or undulate ; petiole usually very thick (7 mm. in diameter); midrib 

 thick (5 mm.), straight, splitting' above into 2 equal branches; secondaries 

 thick, straight, alternate or subopposite, often forking, craspedodrome or 

 subcamptodrome, the secondaries or their branches united by broad loops 

 with branches from the outside to the margin; nervilles very numerous, 

 strong, mainly percurrent, yet often forked or broken ; finer nervation, pro- 

 ducing large, mainly irregular, quadrangular areolse. 



This species is based on a number of fragments that are insufficient to 

 show the true character. Two of the largest are figured, showing what is 

 assumed to be the base and upper portions. The largest is 13 cm. long and 

 about 10 cm. wide, but this could have been only a fragment of the original 

 size. This specimen (fig. 5 of PI. CII) is peculiar in that the midrib splits in 

 the upper portion into 2 equal brandies, both of which are again branched 

 on the outside. This leaf appears also to have been 2-lobed at the apex, 

 all of which may be abnormal and due to an injury to the midrib. The 

 nervation in the upper portion quite markedly camptodrome. 



The lower portion that I have assumed to belong to this species has an 

 exceedingly thick petiole, of which only a fragment is preserved, and also 

 a thick midrib. They appear so different that it seems hardly probable 

 that they can be identical, but rather than multiply unsatisfactory species 

 they may remain as above until additional material can be obtained. None 

 of the margin except the very base is preserved. 



On account of the fragmentary nature of these leaves, I am unable to 

 determine with satisfaction the proper genus to which they should be 

 referred. In this uncertainty I have placed them provisionally under 

 Phyllites. 



Habitat: Cliff on west end of Fossil Forest Ridge; Fossil Forest Ridge, 

 near head of Crystal Creek, various beds; collected by Ward and Knowl- 

 ton, August, 1887, and by W. EL Weed, September 20, 1885. 



Carpolithes osseus Lx. 

 Carpolithes osseus Lx. : Ann. Eept. U. S. Geol. anil Geog. Surv. Terr., 404, 1872 (1S73). 



A very doubtful species, of which the type is lost and the species 

 not since obtained. 



Habitat: "Elk Creek, near Yellowstone River; A. C. Peale, Joseph 

 Savage, and 0. C. Sloane." 



