106 UNITED STATES GEOLOGICAL SUEVEY— TEKTIARY ELOEA. 



that it is impossible to doubt tlieir identity with the European species; and 

 though fig. 15 has the ears somewhat thick, this difference of size is marked 

 also in both the specimens from Spitzbergen. Possibly figs. 16 and 17 of 

 our jilate are referable to the same species. They have been described in 

 Annual Eeport, 1873, p. 410, as Acorus affinis, spec, nov.? Fig. 14 repre- 

 sents a young scape; fig. 15 a is the enlarged ear of fig. 15. 



Habitat.— Creston, Washakie group {Dr. F. V. Hayden, fig. 12); Car- 

 bon (figs. 13 and 14). Fig. 16 is from a specimen from Castello's Ranch, 

 communicated by Prof. Cope, and as this locality is Upper Miocene, its iden- 

 tity with fig. 17, which is from Black Buttes and Lower Eocene, is therefore 

 rendered doubtfuh 



Monocotyledoncs incerta. sedis. 



ERIOCAULON, Gronov. 



EriocaiilonT pornsnm, Lesqx. 



Plato XVI, Figs. 2, 2 a. 



Eriocaulon f 2'orosum, Lesqx., Annual Keport, 1873, p. 396. 



Leaves basilar, rosnlate, spreading, entire, linear-lanceolate, broader in the middle, gradually 

 tapering upward to a slightly obtnee point and downward to the sessile (?) base (not seenj ; substance 

 thick, spongious. 



By the thick, apparently porous and spongious consistence, by the 

 rosulate superposition, and by the form, these leaves are referable to this 

 genus. They, however, differ by their larger size and the appearance of a- 

 middle nerve. As seen in fig. 2 a, enlarged, the middle nerve is traced by a 

 broad, flat depression, along which the veins are parallel, as in some species 

 of this genus; Po'palanthus melaleucus and Eriocnulmn mode.stum of Brazil, 

 for example. The leaves of the fossil species, four to five centimeters long, 

 seven millimeters across in the middle, are broader and longer, and have also 

 the surface narrowly wrinkled across or in an oblique direction to the middle 

 (fig. 2 a), these wrinkles tending downward and passing down along the 

 borders, sometimes like anastomoses of the veins. The base of these leaves 

 is either covered by superposition of others or destroyed; it is therefore 

 impossible to further extend the comparison. Aholhoda poarchon, Sieb., of 

 Brazil, a species of the same group of the Xiridece, also offers a likeness by 

 its leaves to those of this fossil plant. 



Habitat. — Sand Creek {Mr. W. H. Holmes), with leaves of Nelumbium 

 and other species found also at Golden, and therefore of Lower Eocene type. 



