326 REPORT OF NATIONAL MUSEUM, 1884. 



bar vertebrae short ; those of the caudal vertebra, except the first four, 

 rudimentary. Vertebrae : 0.7; D. 13 ; L. 6 ; S. 4 ; Ca. 25 = 55. 



Neofiber Alleni, True. 



Xeofiber Alleni, True, Science, iv, No. 75, 1884, p. 34 ; Proc. U. S. Nat. Mus., vii, 1884, 

 p. 170. # 



A muskrat of less than half the size of Fiber zibethictis, but of the 

 same general form. Eyes small and high up on the head. Ears mod- 

 erate, broad and rounded, hirsute within the conch, the longest hairs 

 extending 0.8 cm beyond the margin. Border of the conch slightly and 

 unevenly notched. Fore feet as in F. zibethicus. Palm black, except 

 the two large posterior tubercles and the base of the thumb. Hind 

 feet moderate, not equaling twice the length of the fore-feet. Soles 

 naked, smooth, black, and 5-tuberculate. 



The posterior internal tubercle large and oval in outline. The remain- 

 ing four, situated respectively at the angle between the 1st and 2d toes, 

 between the 2d and 3d, between the 3d and 4th, and between the 4th 

 and 5th j all small and of equal size. Soles narrow. Toes not in- 

 cliued laterally at an angle with the sole. Fringe of the toes and sole 

 not extending prominently below the plane of their lower surface. 



Toes of the fore and hind feet only slightly webbed. Claws horn- 

 colored. Tail round, about 0.6 cm in diameter at the base and tapering 

 gradually to the tip. Sparsely clothed with short blackish hairs, be- 

 tween which the tail appears covered with rows of scales, as in Mus. 



Color of the hair of the body above as in F. zibethicus; rich rufous at 

 the upper two-fifths and lead-color at the base. In a small area just 

 behind the shoulders the base of the hairs is white. Color of the head 

 the same as of the body, but darker. Hair of the under surface of 

 the body light rufous at the upper third, lead-color at the base. Chin, 

 throat, and inner side of the fore arms and legs white or but faintly 

 tinged with rufous. Fore and hind feet above clothed with short, dull, 

 brown hairs, which extend to the tips of the toes. * 



Throughout its entire structure the Florida muskrat displays an 

 affinity to Fiber on the one side and to Arvicola on the other. It is 

 strictly intermediate between the two genera. 



In general shape the skull deviates in no manner from that of Fiber. 

 The lachrymal pit is less inflated in Neofiber and the nicking of the root 

 of the zygoma in front less obvious. The interorbital area is less con- 

 stricted posteriorly, its sides being nearly parallel. The squamosals are 

 much smaller than in Fiber, and do not approach so near the median 

 line anteriorly. The parietals, on the contrary, are large, and, taken 

 together, heart-shaped, the apex turned backward and truncated. 

 There is a small, regularly triangular, postero lateral extension. The 

 interparietal is broader than long. The zygomatic arches are similar 



* This description is a repetition of that given in the Museum Proceedings (1. c). 



