Ptcropus mascariiius, Mason. 353 



possi])ly be 40 mm,, but must be considerably greater; the 

 latter measurement cannot luive been taken by Mr. Mason in 

 the usual way (from condylion to ^natliion), or, if it has, it 

 is wrong. (2) All the measurements o£ the teeth in the 

 supposed two species are exceedingly alike, with one excep- 

 tion ; in Pt. rodricensis m^ is a trifle (0"l-0*2 mm.) shorter 

 (antero-posterior extent) than p^, in Pt. mascarinus it would 

 seem to be no less than 0*8 mm. longer than/?4; that m^^ in 

 a species of Pteropus, is considerably/ longer than pi, looks 

 sufficiently strange to arouse doubt as to tlie correctness of the 

 statement : but still more strange the character becomes from 

 another point of view ; in all species of Pteropus the width 

 of Wi is (very nearl}/) between two thirds and three fourths 

 the length of the tooth, in Pt. mascarinus the width would 

 be less than half the length of the tootli, and at tiie same 

 time all other teeth, above and below, would be practically 

 precisely similar to those of Pt. rodricenstsl I have not 

 much hesitation in saying that the width of »?i is probably 

 correctly given by Mr. Mason, but there must be some 

 misprint or mistake in his measurement of its length. — If, 

 now, I eliminate the two points discussed above, viz. the 

 condylo-basal length and the length of 7??i in Pt. mascarinus 

 (and I think I am justiried in doing so), there remains a 

 skull which, so far as Mr. Mason's description goes, agrees 

 exactly with tliat of Pt. rodricensis. 



In discussing the probable affinities of Pt. mascarinus, 

 BIr. Mason comes to the conclusion that it " occupies a place 

 intermediate between Pleropus vampyrus [i.e. Pt. Edwardi,i] 

 and Pt. rodricends, in size only, the dentition being typical 

 of Pteropus, whereas the two above species fall into the 

 subgenus Spectrum " ; and " a great analogy, in fact, exists 

 between the dentition oi Pt. mascarinus and those species of 

 Pteropus (tonfjanus, Gouldii, and conspicillatus) inhabiting 

 Australia and the islands of the PaciHc Ocean." A glance 

 at the subjoined table of measurements is sufficient to show 

 that Vt. mascarinus is not intermediate in size between 

 Pt. Edioardsi and Pt. rodricensis, but similar to this latter 

 species. Whether mascarinus is a distinct species or not 

 cannot be decided with any degree of certainty, so long as 

 its external characters are unknown ; closely related species 

 of Pteropus often agree in cranial and dental, and differ in 

 external characters, and the distance between Mauritius and 

 Kodriguc'Z is great enough to make it possible that mascarinus 

 is distinguishable from rodricensis. But so much is beyond 

 ail doubt, that in order to lind " a great analogy " to /*/. mas- 



