402 SMITHSONIAN MISCELLANEOUS COLLECTIONS [vOL. 45 



Subgenus MICROLAGUS Trouessart 



1897. Microlagus Trouessart, Catalogus Mammalinm, i, fasc. iii, p. 660. 



Type. — Sylvilagiis (Microlagus) cincrasccns (Allen). 



Geographical Distribution. — Western and southwestern United 

 States and northern Mexico. 



Diagnosis and Description. — Externally like Sykilagus, size small, 

 skull (pis. lxxvi, 9, 10; lxxvti, i; lxxxvi ; lxxxvii, 11-13) Hght, 

 rostrum rather straight, narrow, pointed ; postorbital process attached 

 to skull by a narrow pedicle, the anterior portion of the postorbital 

 more or less free from the skull, and helping to form a well-marked 

 notch. Posterior portion of postorbital rather slender. It may or 

 may not touch the side of the cranium ; when it does, it incloses a 

 clavate foramen, fully as wide as the posterior limb of the process. 



For the species belonging to this subgenus, see pp. 336, 337. 



Genus ORYCTOLAGUS Lilljeborg 



1867. Ctmictihts Gray, Ann. JNIag. Nat. Hist., 3d sen, xx, p. 225. 

 1874. Oryctolagus Lilljeborg, Sveriges och Norges Ryggradsdjur, i, 



p. 417. 

 1899. Oryctolagus Major, Trans. Linn. Soc. London, 2d ser., vii, ZooL, 



November, 1899, p. 514. 



Type. — Lcpus ciiiiiciilus Linn.eus. 



Geographical Distribution. — Southern and western Europe and 

 northern Africa. 



Diagnosis. — Externally similar to Lepits, but ears and hind feet 

 relatively shorter. Postorbital process large but not wide and 

 triangular ; its posterior limb does not touch side of cranium. 

 Sutures of the interparietal distinct. Choanje very narrow, incisive 

 foramina and least length of palate subequal, width of choanas much 

 less than either. Teeth essentially as in Lcpus. 



Skull (pis. lxxvi, 2, 5; Lxxvii, 5; Lxxxvm ; lxxxix, 1-5). — The 

 postorbital processes are large, but not wide and triangular ; they do 

 not stand out from the side of the skull to a marked extent. The 

 process is arched. Neither the anterior nor the long and rather 

 pointed posterior portions meet the side of the cranium in the wild 

 rabbits. Anterior and posterior notches are thus formed. In two of 

 the skulls of domestic rabbits at hand, a lop-eared and a Belgian 

 hare, the anterior angle of the postorbital meets the frontal bone, and 

 in the lop-ear forms the outer boiuidary of an irregular foramen, 

 while in the Belgian hare the whole anterior angle is fused to the 

 cranium so that even the foramen is obliterated. In both these speci- 

 mens posterior notches are present. 



