1383.4 319 [Cope. 
First premolars only one-rooted ; canine small ; incisor very 
langes. 3% 
OS Ee OMS ew AW Ww eliounas valte lev As bu, sbuliMeomomecdeds ® 
aa, Last inferior premolar with internal tubercle. 
A very large ? canine ; first premolar only, one-rooted....... Microsyops.+ 
A very large ? canine ; first and second premolars both one- 
POOUG COIS Wo sive nye UNAM CuSO Mies NIAID aisisie as Wiehe; Cra TCO ORULONEU Brine 
The genera of Anaptomorphide, which on dental characters includes 
Indrodon, differ as follows : 
%, Incisors three, 
aa. Incisors two, 
First superior incisor with’ inner lobe; no posterior inner 
tubercle on AUPEHION MoOlars 44.004 RIG NUMON Wie ky Petnle Anaptomorphus. 
The superior dental formula of Indrodon is I. 8; C. 1; P-m. 2; M. 4. 
The canine is compressed and acute ; the third premolar is compressed 
conic, and has two roots. The fourth premolar has but one external cusp. 
The external cusps of the true molars are conic and acute, and are con- 
nected with the internal cusp by ridges which form a V. Posterior inner 
cusp distinct on ms. i and ii, a part of the posterior cingulum, Intermedi- 
ate tubercles present, small. The superior incisors are well developed, 
and display no tendency towards the rodent type. A portion of lower jaw 
adheres to the skull, and may belong to the same animal. It supports 
the last two molars. These have two anterior, Spposite, approximated 
cusps. The heel of the penultimate molar is rather large, and has a raised 
edge, which develops low tubercles at the angles. 
Char. Specif. The first and third superior incisors are a little larger 
than the second. Canine preceded and followed by diastemata, each of 
which is 1.5 times as long as the long diameter of the base of the crown. 
Premolars separated from each other and from the first true molar by in- 
terspaces half as long as the diastema. Neither tooth has any basal 
tubercles, but the posterior has a weak external cingulum, which is 
stronger posteriorly. The internal cusp of the same tooth is anterior, is 
acute and elevated. The superior true molars have a strong external 
cingulum, which rises into a small tubercle Opposite the space between the 
external principal cusps. Of the latter, the anterior is a little more conic 
than the posterior, and both are well within the external border. On the 
last molar, the posterior external cusp is continuous with the exte 
termediate tubercle, and forms a cutting edge within the posterior margin 
of the crown. The posterior inner tubercle is rather large, and projects 
further inwards than the apex of tne anterior V on the second true molar, 
but not so far as in the species of Andsonchus and Haploconus. 
rnal in- 
*Proceedings American Philosophical Soclety, 1888, p. 559. 
}Leidy Report U.S. Geol. Survey, Terrs. I. 
Cope, Pal. Bull. No, 84, 
