784 JOURNAL, BOMBAY NATURAL HIST. SOCIETY, Vol. XXVL 



a . Mesopterygoid fossa 

 normal. 

 a^. Mammae more 

 « than six ; coat 



silky, sometimes 

 mixed with 



spines. 

 a^ Tooth-row ac- 

 tual ly and 

 prop ortion- 

 ately longer, 

 more than 10 



mm. ... IV. Dacnomys. 



6^ T o o t h - r o w 

 shorter, less 



than 10 mm. V. Rattus. 

 b\ Mammse 1-2 = 6; 



coat silky ... VI. Cremnomys. 

 b'. Mesopterygoid 

 fossa roofed in 

 anteriorly ; coat 

 spiny ; mammae 

 4—2=12 ... VII. Pyromys. 



h\ Plantar pads less than six. 

 a. Pectoral mammae pre- 

 sent. 

 a\ Mammt© 1—2 = 6. VIII. Grypomys. 

 b\ Mamni^ 2—2=8. IX. Millardia. 

 />". No pectoral mammas ; 

 mammary formula 



0—2 = 4 X. GUYIA. 



b\ Anterior upper molar 

 more than half the tooth 

 row. 

 a'. Bevelled edges of incisors 

 notched ; palatal fora- 

 mina extending back- 

 wards deeply between 

 the molars. 

 a\ Frontal ridges well 



marked XI. Leggadilla 



6^ No frontal ridges, 

 a^ Muzzle shorter ; 



essentially housemice XII. Mus. 

 ^7. Muzzle longer ; 

 essentially junglemice XIII. Leggada. 



