Ptcropus mascaviims, Mason. 353 



possibly be 46 mm., but must be considerably greater; the 

 latter measurement cannot have been taken by Mr. Mason in 

 the usual way (from coudylion to gnatiiion), or, if it has, it 

 is wrong. (2) All the measurements of the teeth in the 

 supposed two species are exceedingly alike, with one excep- 

 tion ; in Pt. rodricensis m^'iB & trifle (0"l-0'2 mm.) shorter 

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

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

 a species of Pterojms, is considerably longer than p^, looks 

 sufficiently strange to arouse doubt as to the correctness of tiie 

 statement : but still more strange the character becomes from 

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

 of »?i is (very nearly) between two thirds and tliree fourths 

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

 be less than half the length of the tooth, and at the same 

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

 precisely similar to those of Pt. rodricensisl I have not 

 much hesitation in saying that the width of Wj 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 mi in Pt. mascarmus 

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

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

 exactly with that of Pt. rodricensis. 



In discussing the probable affinities of Pt. mascarinus^ 

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

 intermediate between Pteropus vampyrus [i. e. Pt. Edwards'i\ 

 and Pt, rodricensis, 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 of Pt. mascarinus and those species of 

 Pterojnis (tovganus, Gouldii, and co7ispicillatus) inhabiting 

 Australia and the islands of tiie Pacific Ocean." A glance 

 at the subjoined table of measurements is sufficient to show 

 that Ft. mascarinus is not intermediate in size between 

 Pt. Edwardsi and Pt. rodriceiisis, 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 

 Rodriguez is great enough to make it possible that mascarinus 

 is di.stingui.shul)le from rodricensis. But so much is beyond 

 all doubt, that in order to iiud " a great analogy " to Pt. mas- 



