3^4 SMITHSONIAN MISCELLANEOUS COLLECTIONS [vOL. 45 



1. Lcpus, with the largest number of species and the most ex- 

 tensive geographical distribution. It contains three well-marked 

 subgenera and a number of species which from lack of available 

 material cannot now be satisfactorily classified. 



(a) Subgenus Lepus, represented by the well-known species, 

 timidus, arctinis, europceus, campcstris, and their allies. 



{h) Subgenus Macrotolagiis, containing the jackass hares of 

 Mexico and southwestern United States. 



( f ) Subgenus Pcecilolagits (new), containing Lcpus amcricamis 

 and the related species. 



2. Syk'ihigus, with two subgenera. 



(a) Sylvilagns proper, containing the wood rabbits or cotton- 

 tails of North and South America. 



{h) Microlagiis, containing a few small forms from western 

 and southwestern United States. 



3. Oryctolagns, represented by the rabbit of the Old World, O. 

 cunicuhis. 



4. Liiiuwlagiis, containing the swamp rabbits and water hares of 

 southern United States. 



5. Brachylagus, a small short-tailed rabbit of western United 

 States, B. idahoeiisis. 



6. Pronolagns (new), containing the cape hare of South Africa. 



7. Rouierolagus, the peculiar little rabbit of Mount Popocatepetl, 

 Mexico. 



8. Ncsolagus, from Sumatra. 



9. Caprolagus, from the southern foothills of the Himalayas. 



10. Pcntalagus (new), from the Liu Kiu islands south of Japan. 

 The family Ochotonidae contains but one existing genus, Oclwfona, 

 with a number of species inhabiting the northern parts or high 

 mountain ranges of the Northern Hemisphere. It contains three 

 well-marked subgenera. 



(a) Ochotona, containing ladaccnsis, and allied forms from 

 central Asia. 



{h) Pika, containing alpina and the North American species. 

 (c) Conothoa (new), represented by roylii and related species. 

 In the preparation of this paper I have received from Mr. Gerrit 

 S. Miller, Jr., many valuable suggestions and generous criticisms, 

 which are here gratefully acknowledged. My thanks are due also 

 to Dr. C. Hart Merriam for the use of all the skeletons and many 

 separate skulls of the Duplicidentata in the collection of the Biolog- 

 ical Survey of the United States Department of Agriculture ; to 

 Dr. Milton J. Greenman for the use of two specimens of Pentalagus 



