106 UNITED STATES GEOLOGICAL SURVEY— TEKTIARY FLOEA. 



that it is impossible to doubt their 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 plate arc referable to the same species. They have been described in 

 Annual Report, 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. Haijden, 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 doubtful. 



Monocotylcdoncs incertck sedis. 



ERIOCAULON, Gronov. 



Eriocaiilon! porosiim, Lesqz. 



Plate XVI, Figs. 2, 2 a. 



Eriocaulonf porosum, Lesqx., Annual Eeport, 1873, p. 396. 



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

 tapering upward to a sligblly obtuse point and downward to the sessile (f ) base (not seen) ; substance 

 thick, spongions. 



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; Pcppalanthus melaleucus and Eriocaulum 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 tlie XiridecB, also offers a likeness by 

 its leaves to those of this fossil plant. 



Habitat. — Sand Creek {Mr. W. II. Holmes), w ith leaves of NelumUum 

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



