NO. 1605. MOUSE DEER OF RHIO-LINGA ARCHIPELAGO— MILLER. 5 



estimate exactly (see map, fig. 2), but the total area which it covers, 

 land and water together, is approximately one-thirtieth of the former 

 and one-twentieth of the latter. Estimating the land area of the 

 archij)elago as one-third of the whole and the relative amount of 

 jungle suited to the needs of Tragidi as the same on the large land 

 masses and the islets of the archipelago, the area inhabited on the 

 archipelago would be about one-ninetieth that on Sumatra and one- 

 sixtieth that on the peninsyla, or only one one-hundred-and-fiftieth 

 of the tw^o combined. Physical conditions on the islands are remark- 

 ably uniform. Lying under the equator they are subjected to no sea- 

 sonal variations of temperature; while the small extent of the group, 

 the uniformity in depth of the surrounding w^ater, and the absence 

 of all influence of great ocean currents preclude the possibility of 

 regional differences. The surface of the islands is mostly rather high, 

 though not sufficiently so to produce altitudinal contrasts of tempera- 

 ture. In his notes Doctor Abbott makes frequent allusion to the uni- 

 formity of vegetation and general conditions from island to island. 

 Slight local changes have been made here and there by cultivation, 

 but never to an extent sufficient to alter the conditions under which 

 the Tragiili exist. 



Notwithstanding its geographic insignificance and its lack of cli- 

 matic or other contrasts, the archipelago is inhabited by no less than 

 eight distinct species of napu ; wdiile from the Avhole of Sumatra, as 

 well as of that part of the Malay Peninsula extending north to 

 Tenasserim, the napus are, so far as known, essentially of a single 

 type." The characters of these animals, some of the more conspicu- 

 ous of which are figured in Plates 1 to 3, are briefly as follows : ^ 



" The common peninsular Tragulus canescens differs very slightly, if at all, 

 from the Sumatran T. napu. In naming it I was under the misapprehension 

 that the napu of Linga Island (T. pretiosus) represented the Sumatran animal. 

 The little-known Tragulus sianlcyanus, from the interior of the Malay Peiun- 

 sula, may for the present be disregarded as perhaps not strictly a member of 

 the napu group. 



* Detailed descriptions of the recently discovered species of Tragiilu>< will be 

 found in the following papers : 



Bonhote, Ann. and Mag. Nat. Hist., 7th ser., vol. 11, pp. 291-290 (hnsci, cvcr- 

 ctti, pierrri=raru.s Miller.) 



Lyon, Proc. IT. S. Nat. Mus., vol. 31, pp. 576-581, (bancanus, hillitonufi, lutei- 

 collis) ; idem, vol. 34, pp. G28-G32 {Jonglpes. fuhncoUif!). 



Matschie, Sitz.-Ber. Gesellschaft Naturforsch. Freunde, Berlin, 1897, p. 157 

 (anna). 



Miller, Proc. Washington Acad. Sci., vol. 2, pp. 227-228 (rufulus) ;-Proc. Biol. 

 Soc. Washington, vol. 13, pp. 185-186 (canescens) ; idem, pp. 191-192 (uinbrinus) ; 

 Proc. Washington Acad. Sci., vol. 3, pp. 113-117 (hunguranensis, palUdus) ; Proc. 

 Acad. Nat. Sci. Philadelphia, 1902, pp. 144-147 (pretiosus, nlgricollis) ; Proc. 

 Biol. Soc. Washington, vol. 15, pp. 173-175 (ravus, borneanus) ; Proc. IT. S. Nat. 

 Mus., vol. 26, pp. 439-446 (amoenus, jugularis, hrevipes, russcus) ; Proc. Biol. 



