338 
A MEMOIR UPON THE GENUS 
slender than that of P. pahidosus ; its cuneiform facet is fiat and oblique. The two 
facets on this metapodial for metatarsal IV are large and placed obliquely to each 
other; internally it shows no facets for metatarsal II. The distal articular surface 
of metatarsal III is more slender than in P. paludosiis, and its tuberosities above the 
trochlea? are less conspicuous. Metatarsal IV corresponds closely to the correspond- 
ing bone in the larger species but is shorter and more slender ; its shaft is strongly 
'bent outwards, and its proximal facet for the cuboid is very flat. 
PAL.EOSVOPS LOXGIROSTHIS pp. IIOV. 
The type of this new species of Palceosyops a jaw% No. 10,2 To, associated 
with a well-preserved radius, ulna, and two metacarpals. All these si)ecimens 
are in the Princeton Museum. The type jaw of this species, with the parts of the 
skeleton associated with it, was referred by Scott and OsboriP to our P. minor (equal, 
in part, to P. paludosus Leidy). After comparing Leidy’s type specimen with this 
jaw, I find that there is such a marked difl'erence in some of its cliaracters that I 
have to give it a specific rank. The following characters distinguish it from 
Leidy’s type. 1. The great posterior extension of the jaAv behind the last molar (this 
is a unique character of this jaw. I have not observed it in any other species 
of this subfamily) . 2. The symphysis is much more elongated than \\\ 1\ minor. 
3. The lower border is straighter and less inflected than in P. minor. 4. The pos- 
terior tubercle of the last inferior molar is much larger than in the last named 
species. 5. The V’s of premolar 4 are not so Avmll developed as in P. minor, and 
there is also a Avell marked diflerence in the size of the first molars of the two 
species. In this jaw the first true molar is considerably smaller than in minor. 
The canine is Amry large and semi-})rocnmbent, its position in the jaAv resembling 
that of T. hyognathus. 
Skeletox. 
Radttts and Ulna. No. 10,275. — The nirper arm-bone of P. longirostris 
is Avanting, but Ave are fortunate in having in the collection both bones of 
the loAver arm, Avhich belong to the same indi\ddual as the jaAv aa IucIi has been 
already described. This radius and ulna liaAm been ah’eady described by Scott and 
Osborn, and I Avill merely insert a comparison Avith the same Ixmes in Limnohyops. 
They are nearly of the same size as in the latter genus. The head of the radius is 
deeper and narroAver than in L. laticeps. The external trochlear is much deeper 
and is not excavated by the radio-ulna facet as in the former species. The total 
length of the radius is much less than in Limnohyops. The internal ridge running 
from the external border of the bone upAvard to Avithin a couple inches of the head 
IS not so Avell marked in this species. The distal articular face of the radius is very 
large as compared with the length of the bone. The styloid portion of the articular 
face IS not so oblique as in L. laticeps. The ulna is also proportionately short and 
heavy. The olecranon is different in form from that of L. laticeps, it being broader, 
’Kept. Prill. Scien. Expert, for 1877, page 37-38. 
