Bills of IlipposiJerus armigcr «/<</ ('ominersoni Types. 35 



V. — On the Bata of the Ilipposidorus annigor (ind 

 Coiniucrsoui Types. By Knlu Andkrsen. 



I. — The IIipposidesus asuioer Tvpe. 



Nasals not inflated, the nnso-frontal region of the skull 

 formiiiff an almost completely flattened pentafpjnal area. This 

 i-< tlie chief peculiarity of the skull iis compared with the 

 diadema type. A facial furainen (for the nerve-supply of the 

 nose-leaves), situated at about the middle of the naso-frontal 

 region, leading into two fine canals, the one extending back- 

 wards, the other forwards, into the bone; rarely (in 3 out 

 of 37 skulls) the canals open by two sej)arate foratnina, the 

 one in front of the other *. The infraorbital foramina 

 slightly wider (not longer) than in //. diadema. 



Dentition essentially as in //. diadema, but a trifle more 

 advanced : — p^ and p^ always in contact, and the cingula 

 almost always overlapping each other, p' very small, ex- 

 ternal to the tooth-row; the canine and ^/ as a rule but very 

 slightly separated or couipletely in contact f. The chief 

 progress, as compared with diadema %, is the more strong'y 

 pronounced reduction, or very often complete disappearance, 

 of the interspace between c andy/ (the former place of /r). 



The wing structure differs in some details from that of 

 diadema and its closest allies § : — whereas the fifth meta- 

 carpal has retained precisely the same length (in proporti(Mi 

 to the forearm) as in diadema, the fourth is somewhat, the 

 third consi(knibly, shortened, making as a total result the 

 third and fourtli equal in length and but sjiglitly longer tliaii 

 the fifth (individually, of course, the fourth metaearj)al is 

 found sometimes a little shorter, sometimes, especially in 

 H. tvrpis, a tride longer, than the third). The proportionate 

 length of the ])halanges is almost as in diadema. 



Posterior leaf narrower than the horseshoe, trilobate ; 

 three vertical ridges on the front face of the leaf. Xo notch 

 in the front border of the horseshoe ||. In one species 



* \ similar fnraracn is found in the bats of the //. diadema typt\ 



t The details, from an examination of thirty-seven skulls, are ttio.«e : — 

 in three c and />' are distinctly, hut rather narrowly, separated ; in -ixteen 

 wlifrhtly or very slightly st-parati-d ; in eighteen in contact, and in three of 

 the^e the cin::iila ovt-rlap each other. 



: Ann. & .Mng. Nat. Hist. (7) xvi. p. 504 (Nov. lOOo). 



§ Coiupare the wing-indices beh>w, on p. 48. 



II A notch in the front border of the horsoshue is found in //. Pratti.A 

 ppecies which bears some external re.«Huiblance to If. armiyer. But the 

 skull of H. Prntti is very peculiar (.sagittal crest raiiing abruptly fur 



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