Genera Microiiyctcris rn/^Z (11} plion^cteris, {\'.\ 



fiont of ilic tooth and tlie vertical is .sliortor than tlic autcro- 

 ])Ostcrior basal diauictcr ; the same is the case in (Hi/jtlio- 

 tiycteris, but at the same time the inner ein^^uliim (lie(;l) of 

 p'^ is more (leve]oi)cd. The canines and premolars, both in 

 the nj)pcr and lower jaw, are peculiarly low, and the antero- 

 internal tubercle of p^ (cusp 6) has disappeared (probaljjv 

 I'uscd with cusp 7). In all these fea'ures Gliiphoni/cteris has 

 evidently arrived at a higlier (le<>ree of s[)ecialization t!i:in 

 Micruni/deris. — The shallow depressions in the basioccipital 

 of a M'icronycteris have become deep jjits in Glyphonycteris ; 

 the anteorbital region is inflated. This, too, is a further 

 development of peculiarities already present, to some small 

 extent, in Microiiycferis. — Ct^-tain external characters aliio 

 bear evidence of a higher s])eeialization : the lengthening of 

 the fifth and third metacarpals (making the fourth the 

 shortest) and the lengthening of the second phalanges, more 

 particularly the second phalanx of the third digit. — But in one 

 respect, at least, Gh/jj/w/iyctei'is seems to be more primitive 

 tlian any known Micrunycteris : in Glyphonycteris there is no 

 transverse band betwcLMi the ears ; in M. Idrsata the band is 

 low, in M. megalotis high, in M. minuta both high and 

 complicated in structure. 



The general result of the study of Gly phony cleris may be 

 epitomized as follows : — It has probably originated from the 

 Micronycteris stem at a period when the transverse band 

 between the ears was still not developed ; in certain characters 

 of the skull, in the dentition, and wiiig-structure it has taken 

 a course of its own, thereby partly further develoi)ing such 

 peculiarities as can already be traced in Micronycteris. — The 

 three species of GlijplwmiCteris are very closely allied. 



The probable interrelations of the bats reviewed above are 

 illustrated in the subjoined diagram : — 



vitnufa. 



mcyalotis. 



hivfiifri. 



Glj/jJt(>n>jcteri.-<. 



