1910.] The Chiroptera; the Primnles. 319 



1907. Gerrit S. jNIiller in his 'The Famihes and Genera of Bats' 

 reviews the history of the classification and the mor])h()logy of the order, 

 defines the famihes and genera and gives extensive keys and synonymy. 

 He recognizes "at least 173 genera and 36 families." 



Genetic Relations. 



The group was very highly specialized as far back as the Eocene and the 

 palcTontological evidence as to its origin is therefore of a negative character, 

 as in the case of the Rodents, Edentates and all other groups which probably 

 acquired many of their ordinal characters before the known Tertiary record 

 began. Nevertheless there can be little doubt that the Chiroptera are an 

 offshoot of late Mesozoic or early Tertiary arboreal Insectivores, which must 

 have resembled Galeopithecus in many characters. This is indicated in the 

 assemblage of characters given by Weber (1904, pp. 382-396), especially 

 the following: Brain macrosmatic, smooth or sparsely furrowed, cerebellum 

 uncovered; testes descending periodically into a subcutaneous cremaster 

 sack; penis pendulus {cf. Primates) often with an os penis {cf. Insectivores); 

 uterus duplex, bicornis or simplex: placenta discoidal, deciduate, with large 

 allantoic chorion and vestigial yolk sack; dentition diphyodont, dental 

 formula a derivative by reduction of |xt|;; teeth primitively tritubercular- 

 tuberculo-sectorial V; digits primitively pentadactyl, carpus with embryonic 

 centrale, tympanic ring-shaped, often connected with the osseus bulla. 

 The ossicula auditus according to Doran (1879) much resemble those of the 

 Soricidae and allied Insectivora, particularly in the malleus, which approaches 

 also the Marsupial type. 



The Microchiroptera are more specialized than the Megachiroptera and 

 the latter in turn are remotely allied to Galeopithecus (see p. 317) which thus 

 serves to connect the Chiroptera with the lycmuroidea and Menotyphlous 

 Insectivora. 



III. The Primates. 



Outline History of the Classification. 



1693. Ray divides the " Unguiculata pede multifido, digitis aliquodque 

 separatis" into: (1) those with flat nails, " IIAaTvwKux" Sc AvOpunrofiop^a, 



1 Oldfleld Thomas has adduced evidence that even the pecuhar molars of the Fruit Bats 

 have been derived from a cuspidate tritubercular-tuberculo-sectorial type (1888, pp. 474- 

 475). This conclusion is supported by Miller (op. cit., 1907, pp. 44-45), who states that in the 

 Phyllostomidse there is "a complete series of stages connecting the normal form of the teeth with 

 one nearly resembling that of the Megachiroptera." 



