360 GEOLOGICAL SURVEY OF THE TERRITORIES. 



Habitat. — Same as Dryophyllum salicifolium, in connection with coal 

 strata of Southwest Colorado, at a higher stage of tbe Cretaceous, 

 M. Holmes. 



These two last-named species have no relation known as jet with 

 any of the Dakota group, and none also with species of the Lower 

 Lignitic or Eocene. Their affinity appears to be with a group of plants 

 known from specimens of tbe upper stage of the Cretaceous of New 

 Jersey. Indeed, the two horizons where fossil leaves have been found 

 in this State, represent, by the lithological composition of the strata, 

 their relative distance, and the characters of their fossil leaves, a striking 

 affinity with what is seen in the stratification, the composition, and the 

 plants of the formation referred above and reported by Mr. Holmes. 

 The Lower Cretaceous of New Jersey is composed, as far as I could 

 judge from the specimens which I examined, of sandy, white, or reddish 

 coarse shale, wherein the plants are imbedded in profusion, but in a 

 poor state of preservation. These represent many species identical 

 with those of the Dakota group, or at least evidently related forms. 

 Both Magnolia Capellini and especially Magnolia alternans, are among 

 them. The upper group, on the contrary, has scarcely any identical 

 species with those of the lower, though the intervening space is not 

 more than one hundred feet; its types appear generally different, and 

 as the vegetable remains are found in a soft clay, the leaves are far 

 better preserved. Among the species of this Upper Cretaceous group, 

 one is apparently closely related to the Dryophyllum described from 

 Mr. Holmes's specimens.* 



FRANGULACE.E. 



Paliurtjs membranaoeus, Lesqx., Cret. Flora, p. 108, PI. XX, fig. 6. 

 Leaf small, membranaceous, oval,- obtuse, entire, palmately three-nerved 

 from the base ; lateral veins thin ; nervilles distinct, in right angle to the 

 veins and joining them. 



Bhamntjs tenax, Lesqx., Cret. Flora, p. 109, PI. XXI, fig. 4. 



Leaf entire, lanceolate-pointed or acuminate, narrowed by a. curve to a 

 short petiole ; lateral veins close, numerous, thin, parallel, camptodrome. 



TEREBINTHAOE^E. 



Juglans ? Debeyana, Heer, Cret. Flora, p, 110, PI. XXIII, figs. 1-5. 



Leaves coriaceous, entire, broadly ovate, obtuse, or with a short obtuse 

 point, rounded-subcordate at the base, or narrowed by a curve and slightly 

 decurring to the petiole ; middle nerve thick ; secondary veins numerous, 

 open, camptodrome. 



It has been remarked, in the introduction, that these leaves may be 

 referable to Rhus. Count Saporta remarks that if there is among these 

 leaves a proportionate number of them with unequilateral base, like figs. 

 4 and 5, they may indeed represent a Juglans or a Juglandites. 



* These specimens were received after my return from New Jersey, where, by the 

 kindness of Dr. G. H. Cook, the director of the geological survey of that State, I had 

 the privilege of examining the numerous materials of the State collection. I have not 

 had yet opportunity of comparing the specimens of Colorado with those of New 

 Jersey, and speak therefore from memory. 



