Cope.] 312 | Dee. 7, 
to near their free summits. There are the usual low marginal tubercles on 
the heels. That of the fourth premolar is a short simple edge. 
Measurements. M. 
Length of four molars on basis...........5+ Aico dis eeaiKipiaiss eS 
cs FT UE OG) UL WG. OLNEY s hie bide aus olasiatts Vssusiwia med Bika ed RLS 
hi VT BGGCMC CMG MONEY Visita sis.e uy malen misirceiocm alain ate -008 
Elevation of cusps of molars........++.+s% si 5G yn than ds ooh ast 0045 
ONGC OF LAS tee TLOVAYs V4 6. wel) 4 wd sbule «o> bib sibenteajelecoOOGG 
Width of last tiwe molars sili. ih Hpac vEsre wad WUUOU: 
Elevation of last true molar in fromt..sscsiceeseescocs 0085 
Found by D. Baldwin. 
Mrocuanus CUSPIDATUS, Sp. nov, 
The species of this genus known to me are, with the present one, nine 
in number, They range in size from that of a rat (M/. minimus) to that of 
a wolf (If. ferox). The general osteological characters of the last named 
species are best known, and are described in the Proceedings of the Amer- 
ican Philosophical Society, 18838, p. 547. In two of the species the supe- 
rior dental series only is more or less known, and one species rests on 
mandibular dentition only. In the remaining seven species the dentition 
of both jaws is more or less known. The species may be arranged in 
groups as follows: 
I. The posterior heel of the second inferior molar bordered by a curved 
edge or crest. 
a, Posterior cingulum of superior true molars obsolete ; If. minimus. 
aa, Posterior superior cingulum weak; JL turgidus. 
aaa, Posterior superior cingulum large, angulate ; IZ corrugatus ; M. 
Seron. 
II. The posterior heel of the second inferior molar supporting a cusp. 
a, Posterior inner cusp of superior molars small, present on m. ii only ; 
M. cuspidatus. 
aa, Posterior inner cusp large, present on m,. i and m. ii; premolars 
small, I. subtrigonus; premolars large, M. opisthacus (Hemithleus mihi 
olim). 
III. Second lower molar unknown. J protogonioides, and M. mandib- 
ularis. 
The supposed M. baldwini, resembles closely the species of Hemithleus. 
It is probable that two genera are here included under the head of Mio- 
clenus. If the character is permanent, these will be distinguished as fol- 
lows : 
Third superior premolar with internal tubercle..............»Mloclanus. 
Third superior premolar without internal tubercle......... «.. Oxyclanus. 
The species of Mioclenus are M. turgidus (type); and very probably 
M. opisthacus, minimus and M. subtrigonus; but the diagnostic tooth has 
not been seen in them as yet. The species of Ovyclenus are: O. cuspidatus 
= 
¥ 
a ES SEARLE Aa 
2 
