1902.] NATURAL SCIENCES OF rHILADELPIIIA. 457 



aratiou of ihe americana group from Ihe Old "World martens. In 

 all the adult representatives of caurina I have examined, this tooth 

 is analogous in character to that of specimens labeled martes and 

 foina in the collection of the Academy of Natural Sciences, and also 

 to Blaiuville's superb figure of zihelUna in Plate 7 of the Osteo- 

 graphie. The character alluded to is the relatively large size of 

 this molar and the wide expansion of its inner bulb or saddle as 

 contrasted with the exterior section of the same, giving the tooth a 

 rounded, emarginate, triangular shape as contrasted with the 

 narrow, rectangular lateral elongation characteristic of the ameri- 

 cana series. In the latter the ratio of greatest breadth to length of 

 tooth is as 5 to 8, in caurina it is as 7 to 9. In a specimen labeled 

 martes from Europe this ratio is 7^ to 9, the numbei*s in all three 

 cases being actual millimeter dimensions of the teeth. Another 

 character in this tooth common to caurina, zihellina and martes is 

 the tendency to a double median tuberculation of the inner bulb, 

 instead of the single elongate tubei-cle always found in americana 

 typicus and its races. This is clearly resultant from the greater 

 width of the inner bulb in caurina and its Old World allies, thus 

 allowing room for subdivision of the tubercle. A further analogy 

 between caurina and the Eurasian, as contrasted with the American 

 type of dentition, is seen in the lai-ge lower sectorial. In the 

 former this tooth is much wider and heavier than in the americana 

 group and the inner median tubercle is strongly developed. In 

 americana it is generally rudimentary, but not always so. 



Some of these chai-acters are pointed out by Dr. Merriam in his 

 original description of caurina, but his statement that the inner 

 cusp of the lower sectorial is wanting in male caurina is disproved 

 by my large series. The skulls of ]Mcrriam's types were not fully 

 adult, however. 



In color, caurina is a richer brown than any of the americana 

 group, more inclining to cinnamon in upper body color. This 

 shade is more uniform throughout the entire length of upper parts 

 to head, which is not so distinctly lighter in color as in all other 

 average East American martens. The head is an almost uniform 

 shade of pale Mars-brown, not lightening on cheeks and ears as in 

 eastern americana types. A marked difference peculiar to caurina 

 is found in the extensive area and rich tint of the dark orange-buft 

 throat and breast patches. This area begins at the angles of the 



