38 Field Museum of Natural History — Geology, Vol. IV. 



Sthenodectes Gregory 



This generic name has recently been applied* to a form of short- 

 headed, massive-jawed titanothere known from the Amynodon Beds 

 (Horizon B) of the Uintah. So far only three specimens have been 

 recorded, all of which are from the same locality and belong to the same 

 species. 



A skull (No. 1 2165) and a pair of lower jaws (No. 1 2166) are included 

 in the Field Museum collection. They were discovered by Mr. Abbott 

 in the lenticular sandstones near Well 2 at the foot of Coyote Basin. 

 The skull (PI. XII, Figs. 1-2) is shorter then the type of S. incisivum but 

 has the broad, low-crowned molars and massive incisors of that species. 

 At approximately the same level and a half mile distant was found the 

 mandible referred to this species. (PL XII, Fig. 3.) It belongs to an 

 older individual, as is evident from the worn molars and incisors. The 

 crowns of the incisors are almost worn away. The mandible is ten 

 millimeters shorter than would be required to fit the skull, but the 

 dentition matches closely. The molars have the strength necessary to 

 oppose the massive upper series ; the canines and incisors, though not so 

 massive as those above, show such wear as would be expected in this 

 form. The canines are worn away diagonally at the point of contact 

 with the third upper incisor, but very little from contact with the upper 

 canines. There is a short diastema between canines and premolars. 

 The mandible as a whole is titanothere-like — deep through the ramus, 

 broad at the angle, concave in the tooth-line and tapering toward the 

 anterior extremity. The coronoid is short and recurved at the tip. 



* Science, Vol. XXXV, p. 546. 





