472 RODENTIA 
expanded, with a corresponding reduction of the parietal and inter- 
parietal, and the interorbital constriction of the frontals attains its 
greatest development. Fossil remains of Fiber occur in the North 
American Pleistocene. 
Neofiber.1—This genus, while agreeing with /vber in the characters 
of the skull and teeth, differs by the cylindrical tail, and the normal 
form of the feet, in which the toes are not bent laterally at an angle 
with the sole. The single species NV. allent, commonly known as 
the Round-tailed Musk-Rat, is found in Florida, and is much less 
completely aquatic in its habits than Fiber. Its colour is brown 
above, and silvery-white mixed with rufous below, the sides of the 
body gradually shading from brown to rufous, the forehead and 
’ the tip of the nose are black, while the tail is rufous mingled with 
black. 
Subfamily Siphneinee. — Includes two genera of Mole-like 
Rodents with an Arvicoline dentition, but with the body thoroughly 
Fic. 210.—Siphneus armandi. (From Milne-Edwards.) 
adapted for a subterranean life, the limbs and tail being very short, 
and the external ears rudimentary. Both are Palearctic. 
Ellobius.2—The Russian £. talpinus, the typical representative 
of the genus, has short claws, and comes nearest to the Arvicoline. 
E. fuscocapilius is from Afghanistan. 
Stphneus.s—This genus (Fig. 210) includes species inhabiting 
Northern and Central Asia, and is characterised by the great length 
of the claws of the manus. Remains of an existing species occur 
1 True, Proc. U.S. Nat. Mus. vol. vii. p. 170 (1884). 
* Fischer, Zoognosia, vol. iii. p. 72 (1814). 
* Brants, Het. Geslact der Muizen, p. 20 (1827). 
