240 Mr. 0. Thomas on Mammals from 



present locality, which is in the district of Aj6, inland of 

 Cape San Antonio, halfway between La Plata and Mar del 

 Plata. 



Eighteen species are represented, and though it might have 

 been supposed that the region was well known, so many points 

 of interest have cropped up that I have thought it best to 

 give a complete list of the collection, besides describing such 

 new forms from other localities as have become apparent 

 during the process. 



1. Nycteris* cinerea viUostssima, E. Geoff. 



S . 2082, 2083 ; ? . 2064, 2088. 



Dr. Allen has again j* revived the question of the identifi- 

 cation of the " Chauve-souris septieme" of Azara, which in 

 1901 I assigned to the Paraguayan representative of the 

 cinerea group, and he later in the same year to the borealis 

 group. On my reaffirming my opinion he has produced a 

 new theory — that Azara's bat was not a Nycteris (Lasiurus) , 

 but a Dasypterus, probably my D. ega argentinus. 



While admitting that this theory has a little more plausi- 

 bility than the borcaKs view, I am not disposed to abandon 

 my original opinion, for several reasons. 



Firstly, if the two theories were of exactly equal proba- 

 bility (and even this I do not think is the case) the cinerea 

 identification should be adhered to as having been the first 

 made by an author who had duly considered the whole subject, 



Secondly, the reputed absence of cinerea from Paraguay 

 cannot be really correct, since it occurs both to the north and 

 south of that country, as I knew when making the identifi- 

 cation. Dr. Allen would seem to have been ignorant of this 

 fact. 



Thirdly, Dr. Allen seems to have been influenced by 

 Rengger's account of his " villosissimus" • but that is entirely 

 immaterial to the discussion, as Geoffroy's name is based 

 solely on Azara's description. 



The border of the interfemoral of these southern specimens 

 of cinerea is not hairy, and Azara's description of the colour 

 appears to me more applicable to the present bat than to the 

 Dasypterus. 



" Found hanging in Tala tree in monte." — C. H. B. G. 



* Lasiurus auctoruui. See Miller, P. Biol. Soc, Wash. xxii. p. 90 

 {1909). 



f Mamm. S. Patagonia, p. 188 (1905). 



