534 MR. W. L. SCLATER ON SOME INDIAN MURID.E. [Juiie 17, 



it is the external posterior, not the internal posterior, cusp that is 

 missing. In Chirojjodomtjs there ai'e three central, three external, 

 and generally two internal cusps, but in some specimens small 

 traces of the third posterior cusp can be seen. The median molar in 

 Mns consists of two central, two external, and two internal cusps ; 

 in Vandeleuria of two central, one external, and three internal ; in 

 Chiropodomi/s of two median, two external, and two internal cusps, 

 with perhaps traces of the third posterior cusp. 



The molars of the lower jaw are much the same in Mus and 

 Vandeleuria, the anterior consisting of six cusps in two rows bi- 

 laterally symmetrical, and the median of four cusps in two rows, 

 also bilaterally symmetrical. In Chiropodomys the condition seems 

 more primitive, as in addition to the cusps present iu Mus and 

 Vandeleuria there is a strong external cingulum present which 

 seems to me to represent the true external cusps present in the 

 upper jaws of the molar. 



Chiropodomys appears therefore to be, so far as the dentition is 

 concerned, a somewhat primitive form combining the dental cha- 

 racters of both Mus and Vandeleuria, and iu addition to that 

 showing distinct traces of the way in which the bilaterally symme- 

 trical molars of the lower jaw of typical Rats have been derived 

 from a form of tooth consisting of a row of central cusps with lateral 

 cusps such as are still found in the upper jaw. 



This speculation is rather supported by the condition of the 

 dentition in Hapalomys, as will be seen below. 



The following are the measurements of a specimen in spirit from 

 Cherra Punji in Assam : — -Head and body 3-35, tail 5-15, tarsus '70, 

 arm and hand I'O, ear-conch "53, muzzle to ear (skull extracted) 

 •90. 



The examples of Chiropodomys gliroides in the Museum collection 

 are from the following localities : — Cherra Punji in Assam, Munipur, 

 and the valley of the Sitang River in Burmah. This species has 

 also been recorded from the Malay Peninsula (Hume coll.), Upper 

 Burma (Doria), Borneo ( Wallace), and Java (Boria). 



31. Hapalomts longicaudatus, Blyth, J. A. S. B. xxviii. p. 296. 



The specimens from which this species was described have 

 hitherto remained, so far as I am aware, unique ; they were pro- 

 cured by Major Berdmore in the valley of the Sitang River in 

 Burma. The following description contains considerable additional 

 matter to the short one published by Blyth (I. s. c.) thirty-one years 

 ago. 



The fur is soft, contains no trace of spines ; it is very long, 

 measuring about three-quarters of an inch on the back ; the basal 

 three-fourths is very dark slate-coloured, the tips a paler chestnut, 

 with few or no traces of longer black hairs. The body beneath, 

 including the chin and the tip of the muzzle, is white with no trace 

 of the slate-coloured bases to the fur. 



The tail is very long, and resembles that of Chiropodomys in 

 being clothed with hairs gradually increasing in length distally till 



