452 BOBSONIA. 



(five species, D. viridis, crenulata, prcedatrix, inennis, nesea); this 

 marks the final phase cf specialization of the postcaniiie teeth in 

 Dohsonia * . 



Falate-ridges (fig. 26). — 5-)-44-3, t. e. five anterior undivided, 

 four middle interrupted in median line, and three posterior. For 

 arrangement of ridges see figure. There appears to be but little 



A 



P. 



Fig. 26. — Palate-ridges. A, Pi^rojnis hypuineUnius ionieni (94.7.14.3), for 

 eomparisun ivitb B, Dubaimia exoleta (97.1.3.18). The "probable 

 houiologiea of the ridges is indicated by the lettering of the figures. 

 Both figures {. 



specific and individual variation. — The homologies of the ridges, as 

 compared with those of typical species of Pterojms, will he readily 



* Milk dentition and honwlogies of incisors. — The peculiar modifications vf 

 the upper and lower incisors and canines so conspicuous in the permanent set 

 of teeth of Dobsonia have not reacted in the slightest degree on the milk 

 dentition. A young B. prcedatrix in the collection (77.7.18.4, forearm about 

 62 mm., as against 111-121 in adults of same species) has tbe following milk 

 teeth (added, in upper aud lower row, the permanent set for comparison): 

 i'^ c p' p* m^ m- 



^ ^ ' -£ — ^ • Four upper milk incisors spiculiform, slightlv 



diidi„dc dpjdpi *' '^ - s j 



'2 c Pi Pa P4mjmjm3 

 recurved, very distinctly spaced (interspaces a little less than 1 mm.), perfectly 

 alike in shape and size. Permanent i'' visible above and estei-nal to di- (jaw cut 

 open), but no trace of a permanent incisor belonging to di^ This appears to be 

 conclusive evidence that the missing pair of upper incisors in the permanent 

 »€v is i\ not i- (compare Boneia, antea, p. 68, in which tbe missing upper 

 inciso? is also i^ ; in the Rousettine branch of Megachiroptera Boneia and 

 ZJoftsoJiJO. are the only genera with 1—1 upper incisors ; in certain specialized 

 genera of the Cynopterine branch it is i^ that is reduced). Middle lower milk 

 incisors (dii) extremely small, barely cutting gum, spiculiform, not recurved, 

 in .perfect contact with each otiier ; outer lower milk incisors (dij) separated 

 from di] (interspace nearly 1 mm.), considerably higher and broader, crown 

 slightly differentiated from shaft. The single permanent lower incisor is 



