Leaf-hearing Terrane hi the Loup Fork. — Cragin, 31 
presumabl.y referable to the Loup Fork ; but these were not ex- 
amined closeh'. 
In the chalk-marl proper, and in the harder and softer phases 
alike, occur dicot3'ledonous leaves, diatoms, fish-remains, and 
moUuscan shells. In the midst of the best-observed outcrop, is 
a local parting or stratum of laminated chocolate-colored shale, 
the relation of whose lamins to those of the chalk-marl pi'oves it 
to be a genuine member of the latter, and not an intrusive deposit 
of later date ; and in this shale, the writer found, together with 
molluscan remains similar to those in the chalk-marl proper, and 
two undetermined genera of aquatic or marsh-plants, the proximal 
end of an ulno-radius which is apparently referable to one of the 
Camelidce, and in an}' event, to an animal as large as Procamehis 
occidentalis, and which had the distal portion of the ulna and 
radius completeh' coossified. This bone has the same chocolate 
color as is seen in the shale itself, and a tooth of Hippotheriiim 
speciosum, which was picked up in a gulh* in the marl -bed. shows 
a state of preservation and color so similar that it can onh' have 
come from the same shale. The ulno-radius itself, however, set- 
tles the age of the leaf-bearing mai'l. Whatever 1)e the genus or 
species, it indicates an ungulate limb of such a kind and degree 
of specialization as, taken in connection with the size, would be 
inconsistent with its reference to any epoch earlier than the Loup 
Fork. That the marl is not later than the Loup Fork, its strati- 
graphic relation to the associated Loup Fork Hippotherium-bearing 
mortar clearl}- shows. 
The white marl itself contains a variet}' of leaves which are, in 
. part, such as it is a surprise to find associated with late Tertiar}- 
mammalian remains, and which promise to shed some light on 
the age of certain Rocky Mountain leaf-bearing horizons. The 
forms of leaves thus far collected from the Alpine chalk-marls are 
identified as follows : 
1 — Platanus sp. tndet., 2 — Plataims aceroides Gopp. 
3 — Salix angustata Al. Br., 4 — Sapindus sp. iiidet, 
o — Populus greviopsis Ward, G — (?) Popidus sp. indet. 
7 — (Jrtdneria daturoefolia Ward. 
Some of the leaf-impressions in this marl retain more or less of 
the lignitized woody material of the leaf, giving a black color to 
those in which a considerable amount of carbonaceous substance 
is thus retained. 
