lvon] the hares and their allies 425 



The skull, as a whole, and in particular the postorbital processes 

 and the palate, strongly suggests the skull of Pronoloi^iis. The 

 structure of the first lower premolar also associates Roiiicrolaii'us 

 with Pronolagns and with Pcnfolagiis as w^ell. Its external charac- 

 ters also associate it with Pcnfalagus but not with Pronolagns. In 

 the shortness of its hind foot, Rouierolagus approaches Pcntalagus' 

 and Ochotona. The sternum of Romerolagus has almost exactly the 

 same form as in Ochotona. 



Genus NESOLAGUS Major 



1897. Caprolagus Trouessart, Catalogus Mamnialiiim, vol. i, fasc. iii, p, 



664. 



1899. Ncsolagtts Major, Trans. Linn. Soc. London, 2cl sen, vii, Zool., 



p. 514, November, 1899. 



1900. Caprolagus (in part) Stone, Proc. Acad. Nat. Sci. Philadelphia,. 

 1900, p. 462. 



Type. — Nesolagns nctschcri (Schlegel). 



Geographical Distribntion. — Sumatra. 



Diagnosis. — Externally essentially as in Caprolagns (Schlegel,. 

 '80, pp. 61, 62). Reentrant angle of second upper cheek tooth ex- 

 tending little more than a third across the tooth, not crenated, but 

 resembling the same tooth in Brachylagns. (Major, '99, pi. 37, 



fig- I7-) 



No specimens of this interesting rabbit have been seen by the 



writer, and the following description is based on the figures given 



by Major and the description by Schlegel. 



Sknll. — Postorbital processes probably like those of Romerolagus, 

 Pronolagns, Caprolagns, and Pentalagns. 



The bony palate is long, the true palate bones forming about its 

 posterior third, its length is greater than the width of the choanse 

 or incisive foramina. The incisive foramina are rather small, their 

 sides approximately parallel, their greatest width less than the width 

 of the choanje. The choanje are wide. The antero-inferior angle 

 of the zygoma is enlarged. (Major, '99, pi. 39, fig. 38.) 



Teeth. — The reentrant angle of the second upper molariform tooth 

 extends but little more than a third of the distance across the tooth ; 

 its sides are not crenated. (Major, '99, pi. 37, fig. 17.) 



Vertebral Colnmn. — Sacro-caudal series of vertebra twelve 

 (Schlegel, '80, p. 64). By considering four vertebra as forming 

 the sacrum, eight caudal vertebrae are left, a smaller number than 

 is found in any other genus of the Leporidae. 



Stcrnnni and Ribs (pi. xcvi, 4).— Presternum considerably 

 enlarged in its anterior third, to about the same extent as in 



