302 DR. KNUD ANDERSEN ON BATS. [Apr. 7, 



25 p. ct. in the noi'thern races. But even if this be so, there is 

 at all events no absolute difference in this respect between 

 A. t. ravas and the true A. t. toltecus, in which latter dichromatism 

 also occurs (see above p. 298). As to the number and persistency 

 of the small palatine perforations, it is a character of no diagnostic 

 value ; it varies from individual to individual quite as much as it 

 does from species to species, 



Artibeus quadrivittatus Pet. 



1865. Artibeus {Dermanura) quadrivittatus Petei's, MB. Akad. Berlin (13 July, 



1865) p. 358. — Tj'pe locality : Surinam. 

 1878. Artibeus quadrivittatus Pet., Dobson, Cat. Cliir. Brit. Mus. p. 521. — 



Surinam; Pernambuco. 

 1888. Artibeus quadrivittatus Pet., Jentink, Cat. Syst. Mamm. p. 209. — Surinam 



(type specimen). 



Diagnosis. — Similar to A. toltecus, bvit upper side of interfemoral 

 and tibia more sparsely haired, and interfemoral averaging 

 somewhat longer. Forearm 41-7-44 mm. 



A. quadrivittatus and toltecus. — In the shape and size of the 

 skull, in che structure, number, and size of the teeth, and in all 

 external characters, A. quadrivittatios is similar to A. toltecus, 

 with these two exceptions : — First, in A. toltectts the upper side of 

 the interfemoral and tibia is densely haired ; in ^4. quadrivittatus 

 the hairs are so short and sparse as to make the interfemoi-al 

 membrane appear almost naked. Second, in the single alcoholic 

 specimen exaixiined of A. quadrivittatus the interfemoral measures, 

 in the middle line, 12*3 mm., whereas the maximum found in a 

 series of ^. t. toltecus is 10'5 mm. ; it probably indicates that the 

 interfemoral averages longer in quadrivittatus. 



The three specimens (two skins) examined are not sufficiently 

 well presei^ved for a detailed description of the colours ; in one 

 the facial stripes are strong, in the others rather indistinct, 



Afeasurements. — On p. 309. 



Specimens examined. — Surinam (one, with skull) ; Pernambuco 

 (two, with skulls) ; from the collection of the British Museum. 



Peters's Artibeus {Dermanura) quadrivittatus, 1865. — Type 

 locality : Surinam ; type in the Leyden Museum.— The essence 

 of the short original description is this : — " Yon der Grosse und 

 dem Ansehen des St. toltecum Saussure, aber mit etwas breiterer 

 und weniger behaarter Schenkelflughaut," and " mit vier weissen 

 Langsbinden auf dem Kopfe." Forearm 40, tibia 14, interfemoral 

 in middle line 9 mm. 



From the above there can be no reasonable doubt as to the 

 identification of A. quadrivittatus. Peters's measurement of the 

 interfemoral, viz. 9 mm., if compared with the length of this mem- 

 brane in a British Museum specimen, viz., 12-3 mm., seems to 

 show (which indeed was to be expected) that in the length of 

 the interfemoral there is only an average difference between 

 A. quadrivittatus and A. toltecus toltecus ; in a series of this latter 

 I find it varying from between 5 and 10*5 mm. (average 7"9 mm.), 



