APPENDIX A. 329 

~  Davatiia (Stenotoma) TeNnuiFotiA, Sw.—In the collections from Porcupine 
Creek, there are several fragments both of barren and fertile fronds, which I cannot 
distinguish from this widely distributed Asiatic species ; I give magnified tracings of 
portions of the fossils for comparison. I have not had recent specimens of the 
barren frond, and my determination is therefore based upon comparison of the fertile 
fronds, for specimens of which from the Himalayas, I have been indebted to the kind- 
ness of D. A. P. Watt, Esq., of Montreal. In any case, this fern is of the type of D. 
tenuifolia, and represents a genus not now found in North America. It is found in 
the same beds with Onoclea sensibilis. It appears to me just possible that the barren 
fronds described by Heer, as Sphenopterts Blomstrandi may be of this species. (PI. xvi, 
Figs. 1 and 2.) 
Equisetacez. 
EquisetuM, sp.—Numerous fragments of an Equisetum, not determinable; but 
similar to L. Arctica, of Heer, from the Miocene of Spitzbergen ; Porcupine Creek. 
PuysaGenia Partatoru, (Figs. 3 and 4,) Heer, Great Valley.—This curious plant 
first described by Heer, from the molasse of Switzerland, consists of cylindrical striated 
stems, with nodes at considerable intervals, and producing whorls of inflated or sack 
like bodies (ampullae,) which may have been of the nature of roots, or of submerged 
hollow leaves, or bladders. Heer seems at a loss to refer it to any definite place, 
but inclines to regard it as submerged portions of an Equisetaceous plant. The 
specimens from Great Valley are not distinguishable, specifically, from those he 
figures. 
Contfere. 
GtyptTostrorus Evropaus, Heer.—Branchlets and leaves, Porcupine Creek. This 
species is common to the Miocene of Switzerland, Alaska and Greenland, and is 
. found in the Fort Union group of Dakota, N ewberry. South Park, Lesq. 
Sequoia Lanesporrru, Brt—Branchlets, leaves and cones, Porcupine Creek ; Dirt 
Hills, R. Bell; McKenzie River, Greenland and Switzerland; also Fort Union group 
and Black Hills, according to Lesquereux. 
THUJA INTERRUPTA, Newberry.—Very abundant at Porcupine Creek, and wood of 
the structure of Thuja is abundant in the lignites with which it occurs. Remains of 
its fruit seem more to resemble that of the western 7h. gigantea than that of the Th. 
occidentalis, which, nowever, the leaves and branchlets are so like as to be soarcely 
distinguishable. This species is characteristic of the Fort Union group. 
Monocotyledones. 
Lemna (spiropeLa) scuTaTa, N.S., (Figs. 5 and 6.)—Fronds round kidney-form, 
entire or slightly undulate at the edges, sometimes an inch in diameter, single or 
grouped. Roots numerous, filiform, proceeding from a round spot near the notch of 
the frond. 
This species is very abundant at the Bad Lands, south of Woody Mountain, where 
it is associated with great quantities of roots, and rootlets, or filiform sub-aquatic 
leaves. It was an aquatic plant with floating disc-like leaves, and I can refer it to 
nothing else than Lemna. 
At the same place is found a smaller tri-lobed frond, with three equal ovate divi- 
sions, and a diameter of three or four lines, It may indicate a second species, but 
as Only a single perfect frond was found in the collection, I hesitate to describe it. 
(Fig. 7, 4.). On the same slab are roots with pinnate or radiating rootlets, and which 
are very common in these beds. 
Puracmites ? sp.—Associated with the above and also at Porcupine Creek, are nu- 
merous indistinguishable remains of reeds and other grass-like plants. 
Scirpus, sp.—Spikes small, numerous, less than a line long, each with four to five 
pairs of incurved lanceolate scales. Bad lands. 
Scirpus, sp.—Another species, with about six pairs of scales and two lines long. 
Porcupine Creek. 
