208 MR. J. LEWIS BONHOTE 0>f THE [ISToV. 15, 



I have been unable to find any further particulars as to its 

 range. 



Our knowledge of this species is so scanty that it is impossible 

 to give any information concerning any changes of pelage it may 

 undergo, but it does not appear to ever become very light. There 

 is a specimen in the British Museum of a uniform deep dark ruddy 

 brown, marked "Siberia, melanistic variety," bvit further material 

 may prove this to be a normal pelage of the species. 



OCHOTOXA HYPERBOREA (Pall.). 



Lepus hyperhoreiijS Pallas, Zoogr. i. p. 152 (1831). 



Lagomys hyperhoreus (Pall.) Wagner, Schreber, Saugeth. Suppl. 

 iv. p. 121 (1844); Waterh. Mamm. ii. p. 30 (1848); Schrenck, 

 Amurlande, i. p. 147 (1859); Radde, Reisen Siid. v. Ost-Sibirien, 

 i. p. 232 (1862). 



Lagomys hyperhoretis^ varr. normalis, ferruginea, cinereqflava, 

 fusca, Schrenck, Amurlande, i. p. 148 (1859). 



Lagotnys littoralis Peters, SB. Ges. naturf. Fr. Berlin, p. 95 

 (1882). 



This species closely resembles the foregoing, except in its much 

 smaller size. The five specimens from vaiious parts of Eastern 

 Siberia which ai'e in the British Museum show a uniformity 

 quite unusual among members of this genus. The general 

 colour above is a light brownish rufous (mummy brown, Ridgw.), 

 which is practically uniform throughout the upper parts, becoming 

 rather purer rufous on the flanks owing to the absence of black 

 tips to the hairs. The under parts are of a uniform rufous-white. 

 The ears are small and scantily covered with whitish bairs. 



Skull. Except in its size the skull bears a close resemblance to 

 that of 0. aljnna. 



Dimensions (approx, from skin). Head and body 160 mm. ; 

 hind foot 26 ; ear 14. 



Skull. Zygomatic breadth 20 mm. ; length of nasals 11 ; length 

 of molar series 7 ; interorbital breadth 5. 



Habitat. Described by Pallas as inhabiting N.E. Siberia, 

 Schrenck has recorded it from the mouth of the river Maia on 

 the mainland opposite Sakhalin, and I have examined specimens 

 from TJssuri, Kentei Mountains in N. Mongolia, and Yakutsk. 



Schrenck describes, under the names given in the synonymy, 

 several varieties of this species. There can be little doubt as to 

 the specific identity of these varieties, and they probably repre- 

 sent the different pelages assumed by this species, but from the 

 material at my command I am unable to give any further 

 information. 



I also provisionally place 0. littoralis, from a similar locality, 

 under the same name, as a large amount of material will be 

 required before these various foi-ms can be elucidated. 



OCHOTONA LADACEXSIS (Gllnth.). 



Lagomys ladacensis Giinth. Ann. Mag. Nat. Hist. ser. 4, xvi. 

 p. 231 (1875) ; Blanford, J. A. S. B. xliv. p. 110 (1875) ; id. Yarkand 



