1852.] 5 
N 
a little larger than the adult D. torquatus; the only measurements that can be 
given are the following, in English inches : 
Distance between the frontal foramina 1:2. 
Third premolar: lateral diameter -45: antero-posterior diameter °4. 
Fourth premolar: lateral diameter -46: antero-posterior diameter °5. 
First molar: lateral diameter °55 3 antero-posterior diameter °63. 
Inferior canine: length 3:75; posterior breadth °48; radius of curvature 2°70. 
Humerus: diameter of inferior extremity 1:52; breadth of larger articular groove, 
-75 ; smaller groove :4; least distance from lower margin of larger groove to fora- 
men *67. j 
Innominatum : diameter of acetabulum 1-2; least breadth of ilium 1:0. 
Femur: length 6°85 ; from fovea on head, to extremity of trochanter major 1:72; 
breadth of tibial articular groove anteriorly °8; transverse diameter of condyles 
posteriorly 1°55. 
Metatarsal: length 2°87; of inferior articular surfaces, lateral diameter -46; 
antero-posterior diameter *57; length of first phalanx 1:25; second phalanx °95. 
Calcaneum: length 2°45: greatest breadth 1°12; from fibular to apical process -91. 
Condyle of lower jaw; breadth 1:2; antero-posterior diameter of articular 
surface °6. 
Prorocua@rvus prismaticus Lec. Am. Journ. Sc. 2nd series 5,105. 
To the description of the teeth of this animal, I have only to add that the fang 
of the canine is very similar to that of Sus babiroussa; the posterior molar bears 
considerable resemblance to that of Sus babiroussa, as represented by Blainville, 
(plate VIII.) although the student will fail to find the resemblance in nature. The 
Anthracotherium tooth figured in Owen’s Odontography, with which I formerly 
compared this tooth, differs in having the lobes connected by an elevated ridge. 
The dimensions of the teeth are as follows, and indicate an animal smaller than 
a Peccary. 
Inferior canine: length of worn surface 1°35; breadth 3; radius of curvature of 
posterior face and margin 2°46. 
First inferior molar : lateral diameter °39 ; antero-posterior diameter :52. 
Last inferior molar: breadth :5,; from posterior lobe to middle lobe -26; to 
summit of anterior lobe °58. 
Notice of a fossil Dicotyles from Missouri. 
By Joun L. Le Conte, M. D. 
The Tooth which forms the subject of this communication, was found with 
some mastodon bones in Benton County, Missouri, and was presented to me by 
Dr. R. W. Gibbes. 
It is a right lower canine, wanting the fang, and attached to a small piece of 
jaw, containing alveoli of three incisors. 
The tooth has precisely the same direction as in D. torquatus, but is somewhat 
less compressed ; the anterior edge is very acute; on the part of the fang which 
remains, no vestige of external and internal grooves exists; the posterior groove 
is well marked as in D. torquatus; on the outer surface of the tooth, nearer the 
posterior than the anterior margin is an elevated ridge, acute at summit, which 
extends along the whole of the enamelled part of the tooth. This character is not 
to be found in D. torquatus ; the very obsolete elevation which exists there being 
a consequence of the continuation of the grooves impressed on the internal face of 
the fang; I have also failed to discover a similar elevated line on the canine of any 
_ species of Sus which has come under my observation. 
As this seems to be a character of sufficient importance to separate the species 
co-existent with the Mastodon, from any now living, 1 would give to it the name 
of Dicotyles costatus. 
Although there is no character in this canine to make a reference to Dicotyles 
more certain than to Sus, yet as the latter genus has not been distinctly proved to 
