1898.] Osboin, Evolution of the Amblypoda. Parti. 207 



This imperfectly-known animal appears to represent a rather 

 small and specialized form in Series II. 



It is distinguished from the type of C. clcphantopits by the 

 straighter and more compressed superior canine observed in the 

 type, by the transverse position of the crests of the inferior 

 molars, and by the absence of entoconid 2. As shown in the 

 Table, p. 199, the measurements of Cope's C. latidcns type are 

 identically the same as those of C. siiiius, although Cope speaks of 

 the latter as being much smaller than the former. 



Cope has suggested the possible association of C. latidcns with 

 the cotype skull of C. elephantopits. It appears to be distinguish- 

 ed, however, by the form and compressed section of the superior 

 canine. It is, however, certainly related to Series II by the sub- 

 triangular form of the canine and the characteristic swelling of 

 the jaw below m3. Unfortunately the types have been tempo- 

 rarily misplaced, and no determination of this question by direct 

 comparison can be made at present. If these jaws should prove 

 to belong to C. elephantopus, the species C. obliqims will have to 

 be revived. 



It will be noted that both types come from New Mexico. In 

 New Mexico, also true Wasatch, we found in 1897 a lower jaw 

 (No. 2563, Fig. 16) of extremely small size, associated with 

 Meniscotheriion, Amhloctonus and Didymictis, which may represent 

 a female of this species. Unfortunately the canines are not pre- 

 served. The total lower grinding series does not exceed 125 mm., 

 so that this is the smallest Coryphodon jaw known ; the last 

 lower molar measures only 30 x 19 mm. ; the posterior crest forms 

 an angle of 85° with the long angle of the jaw; a minute vestige 

 of the entoconid 2 can however be observed. 



22. Coryphodon curvicristis Cope. 



Type, No. 4326, Am. Mus., Cope Coll. Lower jaw fragments containing 

 pm.4 to m.3 ; canine. 



Dcfuiition. — Molar crests transverse. Posterior crest of mTy directly trans- 

 verse, crenulate, depressed. Superior incisors with sharply angulate anterior 

 faces. Canines as in C. testis. 



The systematic position of this species (Fig. 16) is indetermi- 

 nate. It resembles C. latidcns in the transverse crest angulation 



