Collection of Bats from Paraguay. 437 
A. Skull arched, tapering anteriorly. 
a. Two lower incisors. Upper p' absent. 
GATS UZ On ALO CI teste occ ecicn ere cone sicieye sale ond aca arrhd M. rufus. 
(FF AISIVAG, RIENCE da dek ite ornmitcts BAO pact Nk e cite M. obscurus. 
6. Four lower incisors. 
a, Upper p' minute or absent. A median crest. MM. Fosteri. 
6?. Upper p' well developed. No median crest.. M. bonariensis. 
B. Skull flat, broad anteriorly. 
a. Size large. Four lower incisors.............. M. cerastes. 
&, Size small. Two lower incisors.../.......... M. Temminckiz. 
6. Molossus rufus, Geoff. 
Azara’s Chauve-souris sixiéme, on which Molossus castaneus, Geoff., is 
based. 
36,22. Villa Rica. 24th January, 9th and 10th April. 
Azara’s sixth bat, the Chauve-souris chétaine, has been 
generally considered, on account of its “ fil ou ruban aigu 
qui se rend 4 la pointe du museau” and its size (spread 
370 millim.), as being MM. rufus, Geoff., or an allied local form. 
This reference I am, on the whole, inclined to confirm, for 
Mr. Foster’s specimen agrees very well with the descriptions 
both of Azara and Rengger, and may therefore be taken to 
represent M. castaneus. The one flaw in the description, the 
“ blanchatre en dessous,”’ is equally inapplicable to any other 
allied species. 
It is true that with the same exception the description 
would almost equally well fit Molossus Fostert; but as it has 
to be allocated to one or other of the two local species, and 
the present one seems nearer in size, has a more perfectly 
“ lenticulaire ” antitragus, and with only two lower incisors 
is nearer Azara’s “‘ sans ... incisives” than M. Fosteri with 
four, I propose to avail myself of my privilege as first reviser 
and to assign the name castaneus to the species with which 
I think it has most in common. 
Should further material show the Paraguayan form to be 
distinguishable from the Brazilian, the name castaneus will 
then have to be revived for it. 
7. Molossus obscurus crassicaudatus, Geoff. 
Azara’s Chauve-souris dixiéme ; the basis of Molossus crassicaudatus, 
Geoff. 
26,39. Villa Rica. February and March. 
2. Paraguari. 22nd April. 
These specimens are rather smaller and their skulls are 
markedly lighter and more delicate, with smaller brain-cases, 
than those of Brazilian examples, so that I provisionally 
use as a subspecific name the term applied by Geoffroy to 
