Descriptions of East Asiatic Mammals 201 
the Tungting Lake, the home of Lipotes. It feeds upon crus- 
taceans. 
THE RABBITS, HARES, AND PIKAS (ORDER LAGOMORPHA) 
Though rodent-like in certain respects, the Rabbits and their 
allies may have descended from different lineage. The differ- 
ences from the rodents displayed by Rabbits are found in various 
features of the anatomy and in certain types of behavior. Under 
the first heading come the extra set of small upper incisor teeth, 
which stand directly behind the main upper incisors; also the 
fact that comparatively soft, chalky cement fills the folds of the 
harder enamel in the teeth of the Rabbit Order. Under behavior 
comes the fact that in grinding up food the lower jaws are 
moved from side to side, not forward and backward as is usual 
in the rodents. 
The Order Lagomorpha contains two families, the true Rab- 
bits and Hares, family Leporidse, and the Pikas or Whistling 
Hares, family Ochotonidae, much smaller animals with short 
rounded ears. 
RABBITS AND HARES (FAMILY LEPORID.E) 
The Rabbits and Hares differ from their allies the Pikas (pro- 
nounced "peeka"), by their much larger size and larger, some- 
times very large, ears. The hind limbs of Rabbits, unlike those 
of Pikas, are considerably lengthened. The tail, though reduced 
in some species to a fluffy tuft, is always distinct; in Pikas the 
tail is so much reduced as to be concealed in the body fur. 
Rabbits are virtually voiceless. They lack the power to produce 
the whistling call of the Pikas but are able to make a hoarse 
sound if injured. 
With the exception of variations in body size, length of ears, 
and color, the animals of this family bear a remarkably close 
