lvon] the hares and their allies 323 



49589' Sylz'Hagits Horidanus Florida. 



89514" Sylvilagus floridanus malhirus Four Mile Run, Virginia. 



16248^ Sylvilagus floridanus malluvus Carlisle, Pennsylvania. 



49624^ Sylvilagus floridanus transitionalis Monroe county, New York. 



11644^ Sylvilagus niittaUii Fort Bridger, Wyoming. 



92965^ Sylvilagus truei jMetlaltoyuca, Mexico. 



113432^ Sylvilagus niinensis Chapada, Brazil. 



49665^ Sylvilagus niinensis, young Chapada, Brazil. 



74883" Sylvilagus sp Lewiston, Idaho. 



94197" Sylvilagus sp Monitor valley, Nevada. 



49580^ Limnolagus paludicola Florida. 



49645^ Oryctolagus cuniculus Germany. 



49648^ Oryctolagus cuniculus England. 



49386^ Oryctolagus cuniculus, lop-eared Domestic. 



49677^ Oryctolagus cuniculus, Belgian hare. ... United States. 



57954" Romerolagus nclsoni Mt. Popocatepetl, Mexico. 



22972^ Pronolagus crassicaudatus South Africa. 



93695^ Brachylagus idahoensis lone valley, Idaho. 



93596" Brachylagus idahoensis lone valley, Idaho. 



91188" Ochotona (Pika) sa.ratiUs Cabinet mts., Idaho. 



30990" Ochotona (Pika) saxatilis Salmon River mts., Idaho. 



49620^ Ochotona (Pika) saxatilis Oregon. 



49500^ Ochotona (Ochotona) ladaccnsis Hanle district, Ladak. 



Besides these, I have had access to a large number of skulls, 

 mostly of American species. These are indicated at the end of the 

 description of each genus or subgenus. 



The material examined has been altogether too limited for any- 

 thing like complete work on this interesting group of rodents and 

 much more must be compared before a satisfactory determination of 

 various relationships can be made. Yet, in the course of study 

 so many interesting points have been disclosed, some already pub- 

 lished and some apparently never before recorded, that it seems 

 advisable to set forth our present knowledge in as complete a manner 

 as can now be done. 



As an aid to a clearer understanding of the text, the following 

 outline of the classification therein adopted is here given : 



The existing Duplicidentata are considered as composed of two 

 distinct families, the Leporid?e, hares and rabbits, and the Ocho- 

 tonidse, pikas. 



The Leporid?e are regarded as containing the following ten dis- 

 tinct genera, most of which have heretofore been recognized as sub- 

 genera. Two are here described as new. 



^ United States National Museum. 



"United States National Aluseum, collection Biological Survey, Department 

 of Agriculture. 



