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bulletin: museum of comparative zoology. 



adult, and a more recent comparison with specimens of the two species shows 

 conclusively that they are simply adults of planirostris that have lost the small 

 upper third molar. Rehn (Proc. Acad. Nat. Sci. Phila. for 1900, 1901, p. 756) 

 mentions a Brazilian bat of this species that lacked the last upper molar on but 

 one side, and a second that had lost both these teeth. No doubt they are com- 

 monly deciduous in adults. For comparison with specimens from other localities, 

 I have appended the external measurements of two alcoholic specimens, Nos. 197, 

 3076, from Bahia, Brazil (the type locality), and a third, No. 3854, from Rio 

 Janeiro, Brazil, all in the Museum collection. 



MEASUREMENTS OF ARTIBEUS PLANIROSTRIS. 



The following measurements are from the skull of No. 197, adult male, from 

 Bahia: greatest length, 31.6; basal length, 25.5; palatal length, 16.3; inter- 

 orbital constriction, 7; zygomatic breadth, 19; mastoid breadth, 17; mandible, 

 22.5; maxillary tooth row (exclusive of incisors), 11.5 ; mandibular tooth row 

 (exclusive of incisors), 13 ; palatal width outside first molar, 14.3. 



Artibeus grenadensis (Andersen). 



Artibeus planirostris grenadensis Andersen, Ann. Mag. Nat. Hist., 1906, ser. 7, 

 vol. 18, p. 420. 



Mr. K. Andersen has recently named the island form of the planirostris group 

 occurring on Grenada, but gives only the briefest diagnosis and no measurements. 

 Two skins in the collection, taken at St. George, Grenada, are uniformly darker 

 than specimens of planirostris from the neighboring mainland, nearly Prout's 

 brown instead of clove brown, and are quite without indication of facial stripes. 

 Their size is slightly less throughout than in continental planirostris from the type 

 locality and from Panama. The skulls of the Grenada Artibeus are also smaller 

 with slightly lighter dentition, and the second lower molar is very noticeably 

 shorter. 



In one of our specimens the minute third upper molar is present, but in the 

 other it is lacking on the left side, although the empty socket is still visible. In 

 view of the marked differences as compared with its nearest geographical relatives, 

 and its probable limited range, this form may stand as a species. 



