A New Rabbit from Mexico. 173 



family circle of the Leporidse must be extended to include the 

 new member.* 



From the foregoing it will be evident that the new animal is 

 of unusual interest to naturalists. The curious combination of 

 its anatomical characters, the peculiarity of its mode of locomo 

 tion, the oddity of its habits, and the isolation of its home 

 high up on lofty Popocatepetl give it an interest quite apart 

 from that which attaches to most new discoveries. For this 

 reason it affords me special pleasure to bestow upon the new and 

 remarkable genus, of which it is the type, the name Romerolagus, 

 in honor of the venerable Senor Don Matias Romero, Envoy 

 Extraordinary and Minister Plenipotentiary from Mexico, as a 

 slight token of appreciation for the active interest he has taken 

 in the explorations of the United States Biological Survey in 

 Mexico, and in recognition of the many courtesies he has ex 

 tended to our field naturalists during the past five years. 



ROMEROLAGUS gen. nov. 



Type. Romerolagus nelsoni sp. nov., from Mt. Popocatepetl, Mexico. 



Diagnosis. Size small; ears exceedingly short, shorter than in any 

 known species of Lepus ; hind legs and feet short ; skull much as in Lepus 

 (submenus Si/lvilagus), except that the postorbital processes are small, di 

 vergent, and wanting anteriorly, and the jugals much elongated poste 

 riorly ; clavicle complete and articulating with both sternum and scapula ; 

 presternum broadly expanded anteriorly, much broader than long in front 

 of first pair of ribs [narrow and slender in Lepus} ; mesosternum of 3 seg 

 ments [4 in Lepus} ; 6 pairs of ribs articulating with sternum [7 pairs in 

 Lepus~} ; transverse process of 5th cervical vertebra directed straight out 

 ward (instead of backward), its inferior lamella lacking the usual posterior 

 extension ; transverse processes of all lumbar vertebrae broadly expanded, 

 their bases covering entire length of vertebrae ; hypopophyses present on 

 first 3 lumbar vertebrae, but small ; inferior crest of navicular bone short 

 and not produced under base of metatarsal. 



Romerolagus nelsoni sp. nov. Popocatepetl Rabbit. 



Type from Mt. Popocatepetl, Mexico (altitude 3,350 meters or 11,000 

 feet). No. 57949, rT ad., U. 8. Nat. Mus., Dept. Agric. coll. Collected Jan. 

 6, 1894, by E. W. Nelson and E. A. Goldman. Original number 5639. 



Geographic distribution. Boreal Zone of Mt. Popocatepetl, between the 

 altitudes of 3,050 and 3,660 meters (10,000-12,000 feet). 



* It is singular that of the four characters given by Flower and Lydek- 

 ker in the first sentence of their diagnosis of the family Leporidse ("im 

 perfect clavicles, elongated hind limbs, short recurved tail, and long 

 ears " ) , not one applies to the Popocatepetl rabbit. 



