136 [No. 2, 



On the Osteology of Trlmtops peestctts, — ly G-. E. Dobson, B. A., 

 M. B., Assistant Surgeon, S. Jf.'s British Forces. 



(With plate VI.) 

 [Keceived and read 6th March, 1872.] 



The construction of the bony skeleton shows a closer relationship with 

 Phyllorhina than expected by me, when writing my description of the genus, 

 founded on the typical species of which I had not then obtained a perfect 

 skeleton. 



The genus is connected with Phyllorhina, principally, in the relative 

 number and length of the bones of the fingers, supporting the wing mem- 

 brane ; in the relative number and length of the bones of the toes ; in the 

 shape of the iliac bones ; and less markedly in the flattened form and verti- 

 cal height of the nasal bones. In some other respects, especially in the form 

 of the bones entering into the construction of the basis cranii, and in their 

 foramina, its relations are more closely with Bhinolophus, while it differs 

 from both genera, not less importantly, in some peculiarities of structure to 

 be described hereafter. 



I shall, therefore, in describing the bones of the skeleton compare them 

 generally with those of the species of Phyllorhina and Phinolophus, and 

 particularly with those of Ph. larvata, Horsf., portions of the skeleton of 

 which are figured in the accompanying plate for the purpose of comparison. 



In its general outline the skull resembles that of Phyllorhina more 

 closely than Rhinolophus, especially in the flattened form and less vertical 

 height of the nasals, which are, however, relatively, much more developed 

 laterally and vertically, than in the former genus. From both genera it 

 differs remarkably in the form of the zygomata which are greatly compressed, 

 and expanded in a vertical direction. 



The superior margin of the zygoma rises vertically to a height of 0"15 

 inch immediately in front of the posterior origin of the arch, mamtaining 

 this height for more than two-thirds its length, then suddenly narrowing to 

 half near its connection with the maxillary ; the inferior margin is straight, 

 and the intervening bony structure very thin and diaphanous. The zygo- 

 mata are not curved outwards, as in Phyllorhina and Rhinolophus, and their 

 flattened arches form straight lines with the sides of the maxillae. 



The oasis cranii is much narrower than in Phyllorhina ; the basi-occipi- 

 tal is less than half the width of that of Ph. larvata, the total lengths of the 

 skulls being, respectively, 0"85 and 095 inches. 



The following table of dimensions shows the principal measurements of 

 the skulls in Tr. persicus and Ph, larvata ; — 



