386 



lono- and four centimeters broad. The point, as in the former species, is 

 entire, and still more rapidly and acutely acuminate, and the lobes 

 alternate, short, equal and similar, give to this species a beautiful appear- 

 ance. 

 Habitat. — Middle Park, Dr. F. Y. Hayden. 



17. Myrica Lessigiana, sj). nor. 



This species is represented by nearly the half of a leaf, enormous, at 

 least, for the genus. Leaf linear, oblong in outline, deeply lobed ; lobes 

 opposite, ovate-lanceolate, obtusely pointed, at an open angle of diverg- 

 ence, entire, joined at a short distance of the thick middle nerve in 

 obtuse sinuses; lateral veins thick, subopposite on an open angle of 

 divergence, ascending to the point of the lobes, ramified from the middle 

 upward in branches curving to and along the borders ; tertiary veins 

 variable in thickness, relative position and direction, some forking under 

 the sinuses, and passing up on both sides of it; others traversing the 

 large intervals between the base of the secondary veins and the borders 

 of the lobes, and following the borders in multiple festoons; areolation 

 of the same character as in the former species, the large areola?, however, 

 being subdivided in verj- small meshes of the same character. 



This magnificent leaf seems of apellucid texture, though thick ; atleast, 

 all the details of areolation and nervation are distinctly perceivable in 

 black upon the chestnut-color of the leaf. Though the fragment does not 

 represent one-half of the leaf, the terminal leaflet being destroyed, and 

 the base also, still it is twenty-three centimeters long and eighteen cent- 

 imeters broad, each lobe being nine to ten centimeters long from the mid- 

 dle nerve to the point, and seven and a half centimeters broad between 

 the sinuses. This leaf represents, as the former, a species of the section 

 of the ComjHonia, like Comptonia grandi/olia, Ung., which was till now 

 considered as the giant representative of the section, but whose leaf is 

 scarcely half as as large as this. 



Habitat. — Found in connection with a bed of lignite west of Denver, 

 Colo., and kindly communicated by Mr. W. E. Lessig., who discovered it, 

 and had the specimen framed in a bedding of plaster. 



18. Betula YoGDESii, SJ). nov. 



Leaves small, ovate, acutely-pointed, rounded, and narrowed to the 

 petiole, minutely serrulate, peuninerve; lateral veins distant, opposite 

 at or near the base, simple or rarely branching, passing up in an angle 

 of divergence of thirty to thirty-fi\'e degrees, nearly straight tp the bor- 

 ders, craspedodrome ; details of areolation obsolete. 



Habitat. — Near Fort Fetterman, in connection with a profusion of 

 remains of Taxodium distichum, Lieutenant Vogdes. 



19. Castanea intermedia, sp. nov. 



Leaves proportionally long and narrow, linear-lanceolate pointed, nar- 

 rowed to the base; borders equally and sharply dentate; teeth accumi- 

 nate, turned upward; areolation and nervation similar to that of Cas- 

 tanea vesca. By its character it is intermediate between Castanea TJn- 

 geri of the Miocene and C. vesca. 



Habitat. — Middle Park, Br. F. V. Hayden. 



20. Carpinus grandis, Ung. 



This species, so common in the Miocene of Europe, is represented in 

 our flora by a number of leaves identical in all the characters. 

 Habitat.— a!^ear Florissant, South Park, Dr. F. V. Eayden. 



