knowlton.] DESCRIPTION OF SPECIES. 23 
species, however, has the pinnules lobed, rather than crenate, and 
the teeth more obtuse. The secondary nervation is more copiously 
branched, producing more numerous smaller areolations, and thus 
approaching the nervation of W. areolata. 
Habitat. — Point of Kocks, Wyoming, base of bluff, northwest of 
station. Collected September 2 and 3, 1881, by Lester F. Ward. 
WOODWARDIA Sp. 
PI. Ill, fig. 9. 
Outline of frond unknown; pinna oblong, slightly undulate, very 
3btuse at apex; midnerve very strong, grooved; finer nervation of 
numerous irregularly hexagonal areola), becoming smaller toward the 
margin. 
The single fragment figured is all that was found. It is 4 cm. long 
md about 2.5 cm. wide at the base, where it is broken. As may be 
seen, it is very obtuse at the apex. The nervation is that of Wood- 
irardia, although in the figure it has been somewhat idealized, the 
ictual nervation being somewhat less regular than shown. 
At first I supposed that this might be related to the preceding species, 
Dii t the two specimens appear so different that it seems best to keep 
:hem separate, at least until further material can be obtained. I have 
not ventured to name it specifically. 
Habitat. — Coal mine on north fork of Dutton Creek, near old stage 
road, Laramie Plains, Wyoming. Collected by Knowlton, Stanton, 
ind Knight, July, 1896. 
Marsilea? attenuata (Lx.) Hollick. 
Marsilea attenuata (Lx.) Hollick, Bull. Torr. Bot. Club, Vol. XXI, p. 256, PI. CCV, fig. 
10(1894). 
Salvinia attenuata (Lx.), Ann. Rept. U. S. Geol. and Geog. Surv. Terr., 1874, p. 396 
(1876); Tert. Fl., p. 65, PL LXIV, figs. 14, 14a (1878). 
The type of this species is, unfortunately, lost and no other specimens 
lave been obtained. It consists of two small leaves or leaflets joined 
it the base, one of which, the larger, is perfectly circular, 1 cm. in 
liameter, the other being oblong and measuring 8 mm. in length and 
> mm. in width. They have, according to Lesquereux — 
io trace of a middle nerve or of a separation in the middle, the surface beingcomposed 
)f areolae exactly square, formed by veinlets ascending from the base and diverging, 
ind from parallel veinlets crossing them in right angle from the borders. These 
secondary veins are indistinct, and the surface of the leaves appears, with the glass, 
ike a small checkerboard, with squares marked in the middle by an obscure spot 
ipparently formed of round pores, or like a very small wart. 
This description would make out a plant which seems to differ from 
iny known living species of the genus Salvinia. It is hardly closer to 
Marsilea, yet it is perhaps more like that than Salvinia, and for this 
