Affinities I'f "■ Desmalopex " and Pteralopex. 215 



The above are the only cranial cliaracters of Desmalopex 

 given by Miller ; all the other characters (numbers 3-9,, 

 infra) are taken from the dentition. 



(3) " Upper incisors subequal^ distinctly larger than in 

 Pteropus, the cross section of the crown nearly one-third 

 that of canine, the cingiilum produced into a noticeable 

 shelf posteriorly." — In Ft. samoensis, anetianus, pselaphon, 

 pilosus, and tuherculatus the upper incisors are fully as large 

 as, if not larger than, in Pt. leucopterus, and at least in the 

 three last species the cingulura is quite or very nearly as 

 broad as in Ft. leucopterus ; if there is any difference in the 

 development of the cingulum, in favour of Ft. leucopterus, 

 it is certainly infinitesimal. 



(4) " Lower incisors very unequal, the crown area of the 

 outer nearly one-half that of canine, tbat of the inner 

 scarcely more than one-half [probably a slip for one-fifth] 

 as great.'' '' — In a majority of species of Pteropus ig is about 

 once and a half, twice, or twice and a half the bulk of i^, 

 but the contrast in size is in some species much greater, i^ 

 being sometimes four, five, or six times as stout as ij. In 

 Pt. leucopterus the disproportion is due chiefly to an increase 

 of \2 ', the same is the case in Ft. samoensis, anetianus^ 

 pilosus, and tuherculatus, in which \2 is from three to four times 

 the bulk of ij ; in Ft. lombocensis (and a few other species) the 

 increase of ij, is combined with a distinct reduction of ij, 

 making i2 varying from four to six times the bulk of ij, 

 and thus producing a disproportion even larger than in 

 Pt. leucopterus. 



(5) " Small upper premolar well developed, not deciduous, 

 its diameter nearly half that of upper incisor, its crown 

 flat.^^ — The vanishing p^ is a trifle less reduced than usually 

 in Pteropus, though the difference is exceedingly small indeed 

 between Pt. leucopterus and certain specimens of Pt. lombo- 

 censis, in which p' has the crown slightly but distinctly 

 differentiated from the shaft. "Whether p^ is really per- 

 sisten in Pt. leucopterus is impossible to decide on the 

 available material, it would require a much larger series ; 

 all that can be said is that it is present in the only three 



excusable ; it really looks as if the orbits of Pteralopex were moi-e directed 

 upward than in Ft. leucopterus. The reasou is this : — Owing to the 

 excessively heavy canines of li,eralupex, the alveolar border, in the usual 

 position of the skull (lower jaw removed, sliuU resting on a horizontal 

 plane), is much more ascending in postero-anterior direction than in 

 I't. leucopterus ; if, however, the two skulls are kept the one above the 

 other, and witli their alveolar borders parallel, it is very easily seen that 

 the orbits are less upturned in Pieralopex than in iY. leucopterus. 



