(it? rri:7;nns. 



(1) Differential characters, as compared with dentition of Eidolon 

 <iig. 1, p. 3) and liousettus (tig. 2, p. 17).- — Dentition on the whole 

 considerably heavier. Upiier incisors reliitively much larger, with 

 crown distinctly differentiated from shaft, i.^ always conspicuously 

 larger than, generally about twice, sometimes three, rarely four, five, 

 or six times the bulk of, i,. p' rudimentary, stj'lilbrm. generally 

 early deciduous. A pronounced tendency throughout the genus to 

 enlargement of the cingulum of the canines and development of 

 posterior basal ledges in p-\ p', p.^, p^, and m,, these characters 

 being obscured onlj' in certain species with peculiarly weakened or 

 degenerated dentition. Other characters ess^entially as in FA'lolon 

 and lloiisdhis. 



(2) The typical Pteropinc dentition (figs. 6, 9 A, A', 10 A, A'). — 

 Upper incisors nearly equal in bulk and height (i" generally slightly 

 smaller and lower), crowded or very narrowly spaced ; crown 

 distinctly difl'ercntiated. }>osterior basal ledge (cingulum) generally 

 obsolescent in i', narrow but distinct in i'. Diastema i"-c wide, 

 subequal to transverse diameter of lower canine at middle, and to 

 diastema c- p'. Ujqier canines long, siibccjual to ascending branch 

 of prcmaxilla^, slender, gently recurved, in certain species practically 

 straight ; cingulum always distinct, as a rule prominently developed 

 and forming a conspicuous lira oi' ledge at inner and jiosterior base 

 of tooth : front face of crown nuirked by a broad ar'd deep vertical 

 groove terminating a short distance above tip of tooth, inner face 

 by a sharp median keel from cingulum to tij). p' a minute spicule, 

 deciduous, p^ slightly shorter (antero posterior extent) than, but 

 nearly as broad as, p^ ; ])' subrectaiigular in basal outline, distinctly 

 longer than broad ; m' longer and slightly narrower than p' ; m"" 

 much reduced, sulx'qual in cross-section to i\ outline of crown 

 circular or elongate. Posterior basal ledge of p^ and p' distinct but 

 short, marked off ])ostero-e.\ternnlly by shallow notch from base of 

 outer main cusp of teeth. 



Dower incisors crowded or very narrowly spaced, in contact with 

 or separated by minute space from canines ; crown distinctly ditfer- 



fiOO skulls pxaniinecl by llie writer, and represpnling all species and subspecies, 

 only 10 show deviations from llie normal condition ; no less tJian live of these 

 skulls are of Pt. scapulaft'S (total number of sliulls examined, 21). three ot 

 Pt. gic/anleus (of a total number of 29 skulls), two of Pt. vawpi/ru!^ (15 skulls), 

 none of other species. The aberrations found in I't. f/iff'ni/i>iis anti vamptfrus 

 are as follows (on those of Pt. scajmlatug see tliis species, p. 40iJ) : — (1) a well 

 developed " i.,' is present on both sides in one skull of Pt. vampi/rus (B. M. 

 o5.12.26.y0, locality unknown); the right and left i^ are perfectly alike in 

 size, larger than but essentially similar in form to i.,. and situated on inner 

 side of tooth-row, at base of canines ; (2) uij and its alveolus missing on one 

 side: one Pt. vampijrits t'(7«(^)?/r«s (jg. ad., Java, 9.1.0.807) ; (3) ni^ and their 

 alveoli missing on both sides: one Pt. f/ifiantcvs (ad., teeth slightly worn, 

 uncertain locality. 70.3.31.3); (4) an " m^," similar i?i bulk to i., of the same 

 skull, present on one side: one T't . <p(iaiitet(.'< (ad., teeth somewhat worn 

 Bengal, no. ](16.d); nij is in this skull slightly larger thnn usual; (5) " m^ '' 

 present on both sides: one Pt. gigantrus (ad., teeth somewhat worn, Kepal, 

 45.5.15.4 ; mentioned by Dobson, Cat. Chir. B. M. p. Ifi, footnote) : these two 

 "m"'" are very similar in size to m- of a normal skull, whereas "m-" is 

 noticeably larcer than usual, about half the bulk of m' (the iw.«sibili1y thereforf 

 >t*'ing lliul " m- ' ie supernntnerary, and " m ' " homologous with the Moru;al m'- 1, 



