286 MR. C. BODEN KLOSS ON 



( alveoli ), O.C ; median nasal length, 15.0; interorbital bivacltli, 18.2; 

 zj'gomatic Lreadtli, 20 8. 



Remarks. Attention has several times been drawn to the dif- 

 ference between ty|)ieal alrodnri'alis with white vibrissae, which seems 

 to be coiiiiiied to the neighbourhood of Moulmein, and animals iVom sur- 

 rounding districts but no distinction has hitherto been made. 



5. Rattus rattus thai, subsp. nov. 



Type: — Adult female (skin and skull) collected at. Raher.g, 

 Central Siam, on 23rd Januarj- 1917 by Mr. K. G. Gairdner. Author's 

 number 2615/C B K. 



Characlerg: — Mammae 3-3=12 as in Ralliis raitussladeni (Ander- 

 son) from the Kukliyen Hills, near Bliamo, and colour apparently simi- 

 lar but skull with larger bidlae. Skull as in R. r. ne'jlecias of the inoi'e 

 southern jiarts of Siam but coloui'ing rather more ochraceous and wiih 

 an e.xtra pair of pectoral mammae. 



Cdoiir: — Above cinnamon to ochraceous-tawny, streaked by 

 numerous blackish liair-ti))s; base of fur neutral grey. Uelow while 

 tinged with yellowish. Hands and feet butty while, the metapt'dials 

 slightly dusk)- nusially. liars dark. Vibrissae black and wliite. Tail 

 blackish throughout, conspicuously clad with short liairs; twelve rings 

 to the centimetre at mid-length. 



SkuU avd teeih: — As in l\. r. ■ne(jledns of more southern parts of 

 Siam with bullae of the same size or hardly ap|)reniably smaller. 



Speci'viens examined -. — TUe type and an adult male (No. 250.")) 

 from Me Yen. Lakon. North Siam, 1500 ft. collected by Mr Ciairdm-r 

 on 20tli Novendjer 1915. 



Meaf!ure}iienf.s :—Ueaf\ and body, 1C7 ; lail, 170 ; hindfoot, s. u., 

 31 ; ear, 22. 



Skull :— greatest length, 40.2 (41.8)*; coni'ylo-basilar length, 

 3.5-3 (—) ; diastema, 11.1(11.0); upper molar-row (alveoli), 7.0 (7.0) i 

 length of pal-ital foramina. 8.0 (8.0); median nasal length. 14 8 (15.2); 

 breadth of combined nasals, 4.0 (4.2;; zygomatic breadth, 10.5 (10.8). 



Rcmai-li-x : This form seems to liidc up sladeni with the rats of 



Mi'asnit'iii(;iits in pin'i'ntlicses lliosc of No 2-505 



Jullt.N. N.\T. lU.ST. t^OC. .SIAM. 



