knowlton.] DESCRIPTION OF SPECIES. 17 
[atter name, and that it is at present scarcely possible to separate the " Lower Dark 
Shales" of Dr. Dawson's Bow and Belly River Report from the "Fort Pierre and 
Fox Hills " groups on purely palreontological grounds. 
Aii examination of the plants that have been identified from the 
supposed Belly River horizon on the Missouri (see pp. 11-15) brings 
nit some interesting facts. I have identified seven forms. Of these 
>nly two have been identified with previously known species. Thinn- 
c eldia montana and Liriodendron alatum, both of which are true Laramie 
ipecies and have never before been found outside of this horizon. The 
■emaining species have been described as new. Of these Ficus mis- 
•ouriensis is closely allied to Ficus glascccana Lx., a well-known species 
>f the Dakota group. Juglans missouriensis is like certain of the 
eaves of J, rugosa, a Laramie species. Laurus sp. is hardly to be 
eparated from L. Knowltoni, a Dakota group form. Platanus Wardii 
las a number of affinities, the strongest being with Dakota group 
arms. The species described as Quercus ? montanensis is too poor to 
•erinit comparisons that would have any weight. From this it 
ppears clear that not one of the seven forms identified from the 
lissouri River horizon has yet been found in or has particular 
ffinity with species from the Fort Union. They appear to be either 
rue Laramie, as the term is now understood, or to have unmistakable 
ffinity with the Dakota group. 
DESCRIPTION OF THE PLANTS OF THE MONTANA 
FORMATION. 
FUCUS LIGN1TUM Lx. 
PL III, fig. 4. 
ucus lignitum Lx., Bull. U. S. Geol. and Geog. Surv. Terr., Vol. I, No. 5, p. 364, 
(1875); Ann. Rept. U. S. Geol. and Geog. Surv. Terr., 1876, p. 296 (1878); Tert. 
PL, p. 42, PL LXI, figs. 24, 24a; Ward, Syn. Fl. Laramie Gr., p. 549, PL XXXI, 
figs. 1, 2 (1886) ; Types Laramie Flora, p. 13, PL I, figs. 1, 2 (1887). 
The type specimens of this species, together with additional ones 
om the type locality, are preserved in the United States National 
useum. The recent material adds nothing to our knowledge beyond 
ie fact that the new specimens are sometimes a little larger than those 
£ured by Lesquereux. 
The single specimen obtained by Professor Ward atBurns's ranch on 
e Yellowstone River, below Glendive, Montana, while not a perfect 
ample, is with little doubt the same as that from Point of Rocks. 
Habitat. — Point of Rocks, Wyoming 5 moderately abundant. Burns's 
nch, Yellowstone River, near Glendive, Montana; apparently rare. 
Halymenites major Lx. 
ilymenites major Lx., Ann. Rept. U. S. Geol. and Geog. Surv. Terr., 1872, pp. 373, 
390 (1873); ibid., 1873, pp. 379, 384 (1874); ibid, 1876, p. 496 (1878); Tert. FL, p. 
38, PL I, figs. 7, 8 (1878). 
lymenites minor? F. O., Lesquereux in Ann. Rept. U. S. Geol. and Geog. Surv. 
Terr., 1872, p. 373 (1873); Tert. FL, p. 39, PL I, fig. 9 (1878). 
Bull 103 2 
