REVIEWS. 
79 
cal Survey of the Territories, conducted with so much spirit by Dr. F. V. 
Hayden, seeing that the grandest volume that we have to notice, just re- 
ceived, is issued by that department. This, which is the eleventh volume of 
the Report of the Geological Survey of the Territories,* contains a series of 
monographs of the families of North American Rodents by MM. Elliott 
Coues and J. A. Allen, the extreme value of whose work upon the 
Mammals of North America is so well known as to render any praise or criti- 
cism on our part quite superfluous. Our notice of this magnificent volume 
of more than 1,100 quarto pages must be limited to a general indication of 
its contents. The classification adopted by the authors divides the order 
Rodentia into the two well-known sub-orders, Simplicidentati, with two, 
and Duplicidentati, with four, incisor teeth in the upper j aw, the latter in- 
cluding the Leporidse, or true Hares, and the Lagomyidse, Pikas, or Calling 
Hares, both of which families are treated by Dr. Allen. Of the nine 
families into which the much larger group of the Simplicidentati is divided, 
the Muridse, Zapodidse, Saccomyidse, Haplodontidse, and Geomyidse are 
described by Dr. Coues ; and the Sciuridse, Oastoridse, Hystricidae, and 
Castoroididae by Dr. Allen. Of these groups the Zapodidae constitute a 
family established 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 Dipodidae as from the Muridae. 
The family Castoroididae is a new one, proposed for the reception of the great 
extinct Rodent, Ccistoroides ohioensis, the remains of which have been ob- 
tained 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 
(Hydrochcerus) described by Lund, from the Brazilian Bone Caves. 
Each of the above families is treated monographically, its position 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 whole 
concludes with a general alphabetical index to the volume. The illustrations 
consist chiefly of woodcut figures of the skulls of Muridse, which are printed 
on five plates. 
The ninth Annual Report of what we in England should regard as the 
more legitimate doings of the Survey, contains an account of the exploration 
of Colorado and adjacent territories, surveyed in the year 1875. t The actual 
* Report of the United States Geological Survey of the Territories. F. V. 
Hayden, U.S. Geologist-in-Charge. Yol. XI. Monographs of North 
American Rodentia, by Elliott Coues and Joel Asaph Allen. 4to. Wash- 
ington. 1877. 
f Ninth Annual Report of the United States Geological and Geographical 
Survey of the Territories, embracing Colorado and parts of adjacent Terri- 
