Cope.] 86 
Measurements. 
Long diameter end of tibia. 
Short ue Ms tps p(DRAUEVOLSOLY )i ak: fice eon pada a} 
Vertical diameter ungueal phalange at nutritious foramina... 
Transverse ‘‘ “ a . Y 
These claws are similar to those of the M. harlant which have been 
discovered. 
Scrurvus, Linn. 
ScIuRUS CALYCINUS, Cope. 
Species nova. 
Established on two imperfect rami of the under jaw, with the incisor 
and first, second and third inferior molars in situ. The size approxi- 
mates it to the 8. hudsonius, and exceeds that of the S. panolius. The 
forms of the ramus so far as visible, is not unlike that seen in the same 
squirrel. The characters which distinguish it from S. hudsonius, are 
chiefly to be seen in the molar teeth, especially the anterior. The crowns 
of all are deeply cupped, and the tritruating surfaces form anterior and 
posterior narrow bounding bands, which widen outwardly. The margin 
of the tooth is elevated and entire, except externally, where the two 
usual low cusps are separated by a deep notch. In the S. hudsontus 
the interior and exterior margins are both emarginate, each notch sup- 
porting a median cusp, thus forming three on each side. Che anterior 
molar exhibits this character still more strongly. Its crown is a cup as 
wide as long, with high uninterrupted margin, except on the outer side, 
where it is deeply notched, It has but two roots. In 8. hudsontus this 
tooth has three roots, islonger than wide, and has three marginal cusps 
on the inner and outer sides of the crown. 
Length of three crowns m. 0048; length exserted portion of inferior 
incisor m. 607; transverse diameter do. at point of issue m. 0023. 
From the extent of the worn surfaces of the molars, the animal de- 
scribed is adult. The second ramus is of the same size; the dental 
series is complete, and the teeth are worn so as to present a dentinal area 
surrounded by a thin margin of enamel. The outlines of the teeth are 
like those of the first specimen. 
As compared with S. panolius, the species is larger, and differs in the 
form of the m. 1, asmuch as in the case of S. hudsonius. 
JAcuLus, Wagler. 
JACULUS ? HUDSONIUS, Zimm. 
One ramus mandibuli with incisor and second molar preserved. The 
latter nearly resembles the figure in F. Cuvier’s Dents des Mammifers, 
and the ramus is about the size of that of the existing jumping mouse. 
Nevertheless, in lack of specimens of the cranium of the latter, I am 
unable to determine its specific relations, now first found in the Postplio- 
cene. 
