460 The Lemuroidea and the Insectivora of the [ May, 
sented by the anterior lobe of a twin or fissured anterior inner 
Pe 
Fic. 2.—Inferior molar teeth of (2) apa — Leidy, ~ (4) mapa 
gracilis Marsh enlarged ta times linear, from Fig. ae, anterior extern 
cusp; fe, p or externa cusp; az, anterior iinet aia Pi, T teia T usps 
5 = or ciel anterior interna 1 cusp. From Leidy, Report U. S. . Surv 
Terrs., F. V. Hayden in charge, Vol. 1. 
cusp. To simplify the understanding of these differences, I give 
the apei table: 
. Inferior molars qadrituberculate. 
Fourth aot premolar with internal cusp : cusp on last molar opposite ite 
lyopsodus Leidy 
Fourth inferior molar — internal cusp;. cusps opposite .... es arisen Cope.} 
Cusps of last molar alte pisthotomus Cope. 
If. Inferior molars i a 
Anterior triangle not well developed on inferior molars. 
Fifth cusp separated from anterior inner by an apical sega only. . Sarcolemur Cope. 
Fifth cusp separated ; canine distinct; one premolar one-rooted. . Votharctus Leidy. 
Fifth cusp well separated ; canine distinct; two weini one-rooted 
Tomitherium Cope. 
Adapis 
Fifth cusp separated, low; canine incisor- or prem e 
le well poA on all the inferior molars. 
Canine distinct; one premolar one-rooted Pelycodus' Cope. 
Jaws of four species of Hyopsodus are abundant in the Wa- 
satch and Bridger Eocene beds, and a species. from the Puerco 
has been doubtfully referred to it. The 
best known species, the Æ. paulus Leidy 
(Fig. 2), of the Bridger epoch, has the 
jaws as large as those of a rabbit.. The 
i H, vicarius Cope, was smaller (Fig. 3). 
a * Nothing is known of the skeleton of any 
bia ta nee te ha species of Hyopsodus. The only spe- 
River (? Bridger) Eocene of cies of Apheliscus (A. insidiosus Cope) 
: pea, feo den Mes kerr ae found Sa Se Wasatch beds of New 
Report U. exico. It arge teeth in the posi- 
ee ee tion of sectorials, a may be an — 
rant Creodont. Nothing is known of it but jaws. Two species 
-10f uncertain reference to this family and order. 
1 
