408 GEOLOGICAL SIJEVEY OF THE TEERITOEIES. 



CiSSUS LOBATO-CEENATA, Lesqx. 



The specimens exactly represent the species as described from Black 

 Butte, (Keport for 1872, p. 396;) the large leaves, with obtuse teeth or 

 undulate borders ; the smaller leaves, more aputelj^ lobed and dentate, 

 representing apparently Vitis tricuspidata of Heer. In all the leaves the 

 base is truncate, and one of the specimens shows them to be long-petioled. 



Habitat. — Willow Creek and Mount Brosse. 



Corn us impressa, sp. nov. 



Leaves thick, coriaceous, entire, deeply impressed into the stone, reg- 

 ularly elliptical, rounded to a very short, scarcely marked acumen, 

 rounded also to the base, which is broken ; secondary veins on an acute 

 angle of divergence, slightly curving in ascending to the borders, reg- 

 ularly cami^todrome, simple or rarely branching once near the point, 

 and anastomosing in festoons along the borders with strong nervilles; 

 these are in right angle to the middle nerve, mostly simple and contin- 

 uous ; the upper veins abruptly join by a curve the point of the middle 

 nerve. This distinct species is related to Cormis orhifcra by the form of 

 the leaf, which is, however, more elongated, and by its strong nervilles, 

 which are, however, more distant and less ramified ; it also differs from 

 it by the lateral veins curving at a distance from the borders, and less 

 numerous. 



Habitat. — Mount Brosse, Colorado, Dr. Hayden. 



Acer trilobatum, A1. Br. 



Leaf broadly oval in outline, round-cordate at base, 3-obtusely 

 short-lobed, and obtusely dentate on the borders, which are erased and 

 undistinct ; nervation 5 palmate, the lower pairs of basilar nerves being 

 mere thin marginal veinlets; middle nerve branching from the middle; 

 secondary veins in an acute angle of divergence; areolation similar to 

 that of A, trilobatum as figured by Heer, (Flor. Tert. Helv., Ill, PI. cxiii, 

 Fig. 8.) From all the forms of this species, however, the leaf differs by 

 the base rounded and more deeply cordate, and by shorter obtuse teeth 

 and lobes. The middle lobe is broadly taper-pointed. The leaf is also 

 comparable to A. Sismondi of Gaudin. 



Habitat. — Troublesome Creek(?) The specimen is without label, but 

 mixed with those of this locality. 



THIRD GROUP. 



None of the localities referable to the third group had been visited by 

 any member of the explorations of Dr. Hayden in 1873, and no new 

 materials have been added to the flora of this group since the publica- 

 tion of tlie Report for 1872. 



SPECIES OE THE FOURTH GROUP. 



Salvinia cyclophylla, sp. nov. 



Leaf nearly round, slightly cordate or truncate, 21 millimeters long, 

 25 millimeters broad, therefore slightly reniform, very entire ; lateral 

 nerve on a broad angle of divergence, or nearly in right angle to the 

 straight half round middle nerve, scarcely thicker than their divisions or 

 the nervilles, which, crossing the areas in various directions, form an ir- 

 regularly quadrate or polygonal areolation. This species does not com- 

 pare with any fossil one known as yet; it is related by its size to 

 8. Rerissi^ Ett., (Bil. FL, p. 18, PI. 1, Fig. 21,) and by the areolation to 

 8. reticulata, Heer., (Fl. Tert. Helv., Ill, p. 156, PI. cxlv, Fig. 16.) 



Habitat. — Middle Park, Dr. Hayden. 



