PLASTIC CHARACTERS. 



is not found in any recent Fruit-bat (but tliere are more or less 

 close parallels in ilicrochiroptera). A glance at the first table 

 above shows that the third metacarpal was quite ordinary in 

 length, and the discrepancy due to the greater length of the fourth 

 and litth. 



The first phalanx of the third finger was normal ; the second, 

 as usual, by tar the longest of all phalanges, and relatively even 

 somewhat longer than usual in Fruit-bats. The two phalanges 

 of the fourth finger were nearly normal, though the first rather 

 shorter than usual. The first phalaux of the fifth finger w^as 

 normal in length ; but there seems to have been two phalanges 

 distally to this (hence Meschinelli"s statement that the "third" 

 finger, which in reality is the fifth, had three phalanges), and, 

 curiously enough, these two distal phalanges together are equal in 

 length to the single distal phalanx of living Megachiroptera (one 

 might almost be tempted tn think whether these " two " distal 

 phalanges are not one broken into two pieces, but it must be 

 admitted that this suggestion is not borne out by the published 

 plate). 



As a rule in Megachiroptera the fifth finger is distinctly shorter 

 than the fourth, though in a few genera (e. g. Epomops) practically 

 equal to the lourth ; in Archceapteropus it was a trifie longer than 

 the fourth (as in a few Microchiropteia). 



The general conclusions are : — In so far as the second finger had 

 three phalanges, and its terminal piialanx was undoubtedly clawed, 

 the hand of Archceopteropus was a genuine Megachiropteran hand ; 

 and in so far as the second finger was less reduced in length, the 

 hand of the fossil form may be said to be a little more primitive 

 than that of any living bat : and in the features in which it 

 differed, more or less slightly, from that of living Megachiroptera, 

 it rather approached the hand of some Microchiroptera (except, of 

 course, if it really had a third complete phalanx in the fifth finger). 

 [The teeth of Archteopteropus are very little known, but the molar 

 structure is said to have been cuspidate as in normal Micro- 

 chiroptera, a statement that cannot be controlled with certainty 

 from the published plate ; the tail was long as normally in 

 Microchiroptera and in one genus of Megachiroptera, Noioj^teris.'] 



Claw of second fiiKjer. — The claw of the second finger is lost in 

 one (aberrant) genus of the lionseltus section, viz. Do'>sonia, and 

 in three genera of Macroglossinte, Eonj/cteris, Xesoivjcleris, and 

 Aotopteris. Even if tlie claw is absent, the ungual phalanx is 

 always present (rudimentary in Notopteris). 



Membranes. — The lateral membranes arise as a rule from the 

 flanks or, rather higher up, from the sides of the dorsum. In 

 Fteropm, Acerodon, and Stijloctenlum the line of origin lies 

 generally somewhat nearer toward the spine, and in a few species 

 of I'teropus {),ielunopo(jon, papuanus, ueohihet-nicus) the membranes 

 arise verv close together, almost from the sides of the spinal tract. 



