On (he Bats of the Fumilij Mi'^'uclennatiiliC. 115 



Lavia is the more primitive : tlie frontal sliielcl is not so 

 profouiully modified as in Curdiodcrma, ?/«' is quite normal 

 in structure. In Cardioderma the frontal shield attains its 

 liighcst degree of modification, the posterior of the external 

 cusps (cus|) ;?) of wi' is moved somewhat backward, and the 

 nntcro-internal basal cusp of the upper canines, present in all 

 other genera, has quite disappeared. 



Summanj. — Selecting the most ))rimitive of the cranial 

 and dental characters preserved in the five living genera of 

 Megadermatidaj, we are able to draw up a rough sketch of 

 the skull and teeth of the unknowti prototype of the family. 

 It was a bat with the frontal shield not very considerably 

 different from that o( Mer/aderma and Euclieira, with the five 

 primary cus|)s of m* practically of equal siz<', as in the typical 

 molar of an insectivorous bat, and with a small p^. From 

 this type of bat originated, on the one side the Malayan and 

 Oriental Megaderma and Eucheira : frontal shield not largely 

 modified, p^ preserved, but cusp 2 of m^ more or less reduced, 

 cusp ?) more or less moved backward ; and the Australian 

 Macroderma : essentially as Mef/aderma and Eucheira, but p^ 

 lost ; on the other side the Ethiopian Lavia and Cardioderma : 

 molar cusps almost normal, but frontal shield profoundly 

 modified, and p'' lost. 



The subjoined diagram gives a view of probable inter- 

 relations and phylogeny of the genera : — 



Macroderma. 



Cardioderma. 



.■Inn. >(• Mag. X. Hist. Ser. 7. Vol. xix. 



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