188 THE ZOOLOGIST. 
Allen. Of these groups the Zapodide constitute a family esta- 
blished for the reception of a single species—the Long-legged 
Mouse or Jumping Mouse, originally described as a Jerboa, under 
the name of Dipus hudsonius, but which, according to Dr. Coues, 
exhibits characters distinguishing it quite as much from the true 
Dipodide as from the Muride. The family Castoroidide is a 
new one, proposed for the reception of the great extinct Rodent, 
Castoroides ohioensis, the remains of which have been obtained 
from post-tertiary deposits in various parts of North America. This 
animal, which was about the size of an adult black bear, was long 
supposed to have been a gigantic beaver. Dr. Allen, however, 
places it in the Hystricine group. It is the largest known Rodent, 
except an extinct Capybara (Hydrocherus) described by Lund, 
from the Brazilian Bone Caves. 
“‘ Each of the above families is treated monographically, its posi- 
tion in the system being discussed, its genera and species, and the 
habits of the latter, described, and its bibliography given. Under 
some of the families, the extinct North American species belonging 
to them are noticed, and in an appendix Dr. Allen gives a list of 
the known extinct Rodentia of North America, with short notices 
of those not referred to in the monographs. A second Appendix 
contains a valuable bibliographical list of works relating to 
North American Mammals, by Dr. T. Gill and Dr. Coues; and the 
volume is illustrated chiefly with wood engravings of the skulls of 
Muride.” 
The Fur-bearing Animals: a Monograph of the North American 
Mustelide. By ELLiotT Cougs. 8vo, pp. 348. Washington, 
1877. 
Tuis is another of the American Government publications, of 
smaller size than the work last noticed, but of no less importance 
and value. It forms Volume VIII. of the ‘Miscellaneous Publi- 
cations’ issued by the U.S. Geological Survey Department, under 
the able superintendence of Dr. Hayden, and, relating as it does 
to a group of animals on which a large majority of mankind are 
more or less dependent for warm covering, it may be said to 
possess a greater interest for the general public than most scientific 
works of the kind usually do. 
