On some of the Characters of the Miocene Fuuna of Oregon. 
(Read before the American Philosophical Society, November 15, 1878.) 
By E. D. Corr. 
We have been for some time in possession of information as to the ungu 
late forms which inhabited Oregon during the Miocene period. Through 
the labors of Profs. Leidy, Marsh and Bettany, we have learned of the 
existence there of Orcodontide@ in considerable variety ; of Anchithertide ; 
of peccary-like species ; of Hlotheriwm, and of Rhinocerus. But of the un- 
guiculate types, of Medentiv, and of the inferior orders of Mammalia, 
almost nothing is yet known. Having recently received a number of 
specimens from the deposits in question, I am in a position to offer a 
number of new identifications. The following species already known 
from the Miocene of Colorado, I find contained in the collection, viz.: 
Paleolagus haydeni; Canis gregarius ; Cunis linpincottianus; Hyper- 
ragulus calearatus ; Leptomeryx evans? 
RODENTIA. 
STENEOFIBER GRADATUS, sp. nov. 
This species is represented in my collection by a cranium which is nearly 
perfect, the principal deficiency being the absence of the mandibular rami. 
It is of smaller size than the S. nebruscensis and S. pansus, and differs from 
both these species in the relative sizes of the superior molar teeth. The 
first of these is the largest, and the others diminish regularly in size to the 
last, whose grinding face does not present more than one-third the ex- 
tent of that of the first. The triturating surfaces of the second and 
third have their long axes transverse. In all the crowns, besides the in- 
ternal and external enamel inflections, there is but one fossette, which is 
anterior to the external inflection. The latter has become isolated from 
the superficial enamel on the last three molars, by attrition. The superior 
incisors are flat anteriorly with the external angle rounded, and its dentine 
presents the transverse undulations seen in S. punsus. 
Measurements. M. 
Length of skull from incisive alveolus.........+.-++-+ 0500 
Width between summits of first molars............... .0060 
“ s fOUTE “par meeawaere a4 a 0095 
Length of molar series. ....... eee eee eee ee eee eee ee £0115 
Diameter of the first molar ‘ antero-posterior. .......- -0040 
AVANSVEPSE. a. via manieas ys 0045 
ine ao 002 
Diameter of third molar { antero-posterior ............ 0028 
ENUNBSVETSE: as svagveeennceaus 0032 
‘ ro . Ss! 2 
Diameter of fourth molar f antero-posterior. ......-..+ .0020 
UAPATISVETSE s cssscisce ecnewis 22's 0024 
From the above measurements it is apparent that the molar scries in this 
species is equal in length to the anterior three molars cf the S. nebrascensis 
