Fruit- liiit-i i]f lilt- ii''nns I )ul).sijiiia. ')'.)]) 



III. / 'rimart/ Sertiotis of Genus. 



The premolars aiul molars of Dobson'ia present four 

 diffiTcnt phases of spcrializjitioii, which may be utilized for 

 a suhdivisiou of the genus int(j four apparently natural 

 sections, as follows: — 



(1) D. minor section: — Premolars and molars simple, 

 i. e. no distinct posterior basal led};e (a sli;;ht indication 

 sometimes seen in [j^ and \\\\), no distinct antero-intcrnal basal 

 cusp (a faint indication may be seen in p*), no trace what- 

 ever of surface ridges. One species, D. minor (N.W. New 

 Guinea'!. 



(2) J), mo/urccnsis section : — A well-developed j)osterior 

 bastd ledge in p^, p*, 1)3, and j), ; a well-marked antero- 

 intcrnal l)as:d ledge or cusp in p' and p*, generally at least a 

 trace of a similar ledge in pa and p^, but never in m, ; 

 surface ridges in m' and mg, sometimes also in p^ and nii. 

 Four species : — D. exoleta, panniclensis, molitrceusis, and 

 innyna. D. e.roltta (Celebes) and pannietcnsis (Islands S.]']. 

 of New (luinea), though geograi)l)ically widely separated, 

 are evidently closely related; the broad intervening area is 

 occupied by the allied but much larger D. moluccensis 

 (.\mboina group and Aru Islands) and magna (New Guinea). 



(.'3) D. pcroni section : — I'issentially as foregoing, but with 

 a strung antero internal ledge also as in m,, but not in m'. 

 Two species, D. peroni (Flores, Timor, Alor, Wetter) and 

 sumhnna (Sumba). 



(1) D. viiidis section : — Essentially as foregoing, but a 

 strong antero-internal ledge also in m^, this ledge therefore 

 well-ditrerentiated in p^, p*, m', pj, j),, and nij ; posterior 

 basal ledges still more strongly developed, as are generally 

 also the surface ridges ; outer and inner longitudinal ridges 

 of p*, m', pi, and m, (or at least some of these teeth but 

 rarely also p' and ps) showing a more or less distinct tendency 

 to break up into two or three separate cusps. Five species : — 

 D. viridis (Amboina group and Key Islands), crcnulata 

 (Gilolo group), pr<pdatri.v (liismarck Archipelago), nesea 

 (\V. and C. ."Solomon Islancls), and inermis (E. iSolomon 

 Islands). Althoiigh, as here indicated, the section is repre- 

 sented in the Moluccas, Bismarck Archipelago, and JSolumou 

 Islands, no species with similar dental characters is known 

 from New Guinea. 



Ann. d: Mnj. X. Hist. Scr. 8. Vol. iv. 3S 



