DE^iCEIPTION OF SPECIES— ENSATiE. 97 



leaf, the veins apparently converge toward the middle, as it happens some- 

 times at the top of a middle effacing nerve. Tlie lovv^er fragment of fig. 2. 

 pertains to the same leaf split in the middle; it has its borders still more 

 distinctly defined. The specimens bear these crushed leaves generally mixed 

 with fragments of rhizomas and radicles (fig. 6), whose ultimate divisions are 

 short, capillary, and so numerous that they cover sometimes whole specimens 

 as by a thick felt, so that every kind of form and every trace of the stone are 

 obliterated. The rootlets are linear, flattened, resembling those of Phragmites 

 CEningensis, while the rhizomas, or perhaps their primary divisions, measuring 

 seventeen millimeters in thickness, are straight, narrowly striate, like the 

 diverging branches of fig. 3, exactly linear, with branches half as thick, passing 

 down in an acute angle of divergence, bearing rows of somewhat distant scars, 

 formed by double, deep, circular lines and a central vascular point. These 

 roots and rootlets evidently pertain to this species, for the leaves of Sapindus 

 ohtusifolius are rarely mixed with those of this Musophyllum, and are found 

 separately and in profusion at a little distance of the same bed of shale. Mr. 

 Cleburn, who visited the same place, collected only leaves of SajJindus, with 

 a single one of Alnus Kefersteinii and no fragments of Musophyllum. The 

 surface of the leaves of our species is sometimes covered with parts of the 

 epidern}is, which, seen with a strong glass, appears marked crosswise with 

 thin veinlets, as in M. bilinicum, YAt. (Bil. Fl., p. 28, pi. vi, fig. 11). But 

 in this last species, the veins are not in an acute angle of divergence to the 

 midrib, and then open and in right angle to it, a character remarked in the 

 American form, and also in M. hohemicum, Ung. (Sillog., p. 8, pi. 1, fig. 13), 

 which, however, differs by thinner, still closer veins, without cross-veinlets. 

 Another species, M. speciosum, Sap. (Et., i, p. 77, pi. v, fig. 2), is repre- 

 sented by a fragment without middle nerve, the veins being thin and crossed 

 by veinlets, and therefore of the same character as in the American species, 

 differing, however, by the position of the veins, very oblique to the borders. 

 This last species is Upper Eocene, or from the Gypses of Aix; the others 

 Miocene. 



Habitat. — Shale over a thin bed of coal, eight miles southeast of Green 

 River station; refei'able to the Washakie group. 



ENSAT^. 



This class of plants, and that of the Fluviales, so abundantly represented 

 in the flora of the present time, have left very few traces of their life during 



7 T F 



