Mr. 0. Thomas on Three new Bats. 385 



The common mainland form is the largest, with a forearm 

 measurement of 95 mm. and upwards, and with the lower 

 tooth-row (front of canine to back of m 3 ) about 15 mm. It 

 has four well-developed supplementary leaflets, and often the 

 rudiment of a fifth. In coloration it has the brown and white 

 markings described by Peters well defined and distinct, except 

 in such individuals as have the reddish suffusion so often 

 found in members of this genus. 



Its synonymy appears to be as follows : — 



Hipposideros Commersoni gigas } Wagn. 



Rhinolophw gigas, Wagn. Syn. ThyUorhina vittata, Peters, and 

 Phyllorhina Commersoni, var. marungensis, Noack. 



In Madagascar the typical II. Commersoni, Geoff., is found : 

 small (forearm about 80-90 mm. ; lower tooth-row about 13) ; 

 supplementary leaflets three, the rudiment of a fourth being 

 occasionally present ; coloration dull greyish, with but little 

 indication of the characteristic dark dorsal markings. 



In the island of San Thome, on the opposite side of Africa, 

 is found a somewhat similar form, //. Commersoni thomensis y 

 Bocage, which agrees with true Commersoni in essential 

 characters, but is even darker, and has a prominent whitish 

 spot on each shoulder at the insertion of the antebrachial 

 membrane. 



Finally, in British East Africa and Zanzibar there occurs 

 a form agreeing with Commersoni and thomensis in size, but 

 with the four leaflets of gigas and well-defined colour- 

 markings. It may be briefly diagnosed as follows : — 



Hipposideros Commersoni mostellum, subsp. n. 



Size small, as in Commersoni. Supplementary leaflets 

 four, with rudiment of a fifth. General colour whitish, the 

 brown Y-shaped marking of the back well defined ; under 

 surface creamy whitish, a brown line across each shoulder 

 separating off a white patch at the insertion of the ante- 

 brachial membranes. 



Skull and teeth as in true Commersoni, the cheek-teeth 

 conspicuously smaller than in gigas. 



Dimensions of the type (measured in skin) : — 



Forearm 92 mm. 



Skull : length from cingulum of canine to back of occipital 

 crest 32 ; basal length to cingulum of canine 26*5 ; zygo- 

 matic breadth 18; mastoid breadth 15; upper cheek-teeth, 

 front of p 4 to back of m 3 8*4 ; front of lower canine to back of 

 wi 3 13. 



