1896.] NATURAL SCIENCES OF PHILADELPHIA. 391 



angle, latter projects as far posteriorly as the condyle. The condyle 

 is rather elevated, its inferior border being in the horizontal line of 

 the apices of the cusps of the sectorial. The coronoid process pre- 

 serves its anteroposterior width to near the apex, which is broadly 

 rounded, and not contracted, as in Lutra species. There is a longi- 

 tudinal keel on the inner side of the angle, distinct from the inferior 

 margin. 



The teeth form a continuous series, the anterior premolars not 

 overlapping. The canine is rather small ; the crown is somewhat 

 compressed, and is not grooved or facetted, but is smooth. The 

 second premolar has the heel produced backward. In the first pre- 

 molar the heel is a cingulum, and is not produced. The metaconid 

 of the sectorial is represented by a convexity of the internal edge of 

 the protocone. Heel concave, with an elevated border on the 

 internal edge only. This consists of a larger lobe or entoconid, and 

 a smaller between it and the lobe representing the metaconid. 

 Entoconid not elevated, resembling that of the extinct species of 

 Mephitis alreiidy described. No cingula. The tubercular molar 

 has a semicircular concave grinding surface, and no cingulum. 



Measurements. m. m. 



Length of ramus from canine to condyle inclusive ; 42 



Depth of ramus at Pm. j ; 7 



Depth of ramus at M . ^ 8 



Depth at condyle ; 7.5 



Depth at coronoid process ; 22 



Length of dental series ; 25 



Length of true molars ; 12 



Diameters of base of crown of canine ; 3.5 



Elevation of crown of canine ; 4 



! elevation ; 3.5 



anteroposterior; 8.5 



width of heel. 3.5 



The jaw described is about the size of that of the common skunk. 

 Lutra rhoadsii sp. nor. 



Portions of both mandibular rami with the right superior tuber- 

 cular molar represent this otter. The right ramus supports part of 

 one of the premolars, a large part of the sectorial, and the tubercular. 

 The left ramus supports the tubercular. In the right ramus the 

 alveoli of the premolars and part of that of the canine are preserved. 

 All belong to one individual, aud were found in place in the 

 matrix. 



