284 PROCEEDINGS OP THE ACADEMY OP 



One individual, young . No. 5537 Mus. Smithsonian Institution. Alcohol. 



Fort Yuma. Maj. Gen. G. H. Thomas, U. S. A* 



This last group includes those given in my monograph as varieties of V. 

 nitidus, where I proposed that the name V. oregonensis, which was attached to 

 one of the specimens, should be retained, in the event of their proving to be 

 distinct. Now that it appears probable that there is a group of closely allied 

 species of Vespertilionida3 inhabiting the southwestern portions of the United 

 States and Mexico, of which V. nitidus is a member, I have concluded to place 

 the so-called V. oregonensis under one of this group, V. obscurus, and give, pro- 

 visionally, new names to the others. " V. oregonemis" bears no locality. As 

 regards the distinctions between the above specimens and V. nitidus, it will 

 be seen that the prevailing deep-plumbeous basal half of the fur above, with 

 its % rich chesnut, olive brown, or, in some specimens from New Mexico, a 

 sandy-chesnut tip, and the lighter shades of the same colors to the fur be- 

 neath, sufficiently serve. The superior border of anterior nares is semicircular ; 

 the 2d premolar of upper jaw wedged in between 1st and 3d to a degree pre- 

 venting it from being visible in profile fror% buccal side. 



A revised description of V. yumanensis is also given, to correct some errors 

 in the original notice. The representation of the tail and interfemoral mem- 



* Compare the above descriptions with V. hypothrix, D'Orb. Smoky brown, deeper above than 

 below, where the fur is mixed with grey. Hab. Moros, Bolivia. 



V. Isidori. D'Orb. Glazed greyish fawn at tip of fur above, brownish black at base. The brown 

 is more marked on shoulders and back of neck. The head is also browner than that of the back 

 and loins, but less than that of the shoulders; the cheeks and parts beneath neck passing to 

 brownish cinnamon. Belly is dirty grey, with base brownish black. Hab. Corrientes, S. A. 



V. brasiliensis, Spix. Size of V. subulatus. Black. Tail exsert. Hab. Brazil. 



V. mexicanus, De Sauss. Gilt brown, with brown at base; beneath grey or pale, with blackish 

 base; eleven joints to tail. Hab. Mexico. 



The following is drawn up from personal examination of four dried specimens collected by Mr. 

 Sumichrast at Orizaba, Mexico. 



Fur: Above, long, silky, plumbeous or deep blue slate at basal two-thirds, with obscure chest- 

 nut or dark brown at apical third; a very small patch of fur on interfemoral membrane; none on 

 wing membranes. 



Beneath, fur short, thickly set; basal three-fourths dark plumbeous; apical fourth uniform grey 

 or dirty yellowish brown. 



The skull is slightly crested at venter; proportions larger than other American species of Ves- 

 pertilio. 



V. chiloe>tsis, Waterhouse. Reddish black. More or less greyish on belly, (Castelnau :) rich 

 brown, (Waterhouse.) Upper incisors nearly subeqraal ; outer side of tragus obscurely crenated. 



Hab. Chiloe Islands, and extending upwards in Brazil (?). 



V. kixnamon; Oervais. Reddish cinnamon, deeper above than below ; tragus curvilinear at 

 lower part of outer border. 



Hab. Capellanova, S. A. 



V. arsinoe, Temm. Fur short; above black: beneath, blackish brown; points of hair "fallow;" 

 whitish at region of coccyx, so as to form here a whitish margin. No emargination on outer 

 border of ear. 



Hab. Surinam. 



V. albescens, Geof. Upper parts black, portion tipped with greyish in part. Inferior parts 

 black, tipped with whitish towards the pubis and coccyx. Hair above entirely blackish, not grey- 

 ish or fawn tip. 



Hab. South America. 



V. iacteus, Temm. Blackish brown at base above ; reddish brown at base beneath; tip whitish 

 both above and beneath. 



Hab. North America (?). 



V. parvulus, Temm. Prevailing tint black, with isabel tint on thighs. 



Hab. Brazil. 



V. polvthrix, Isid. Deep brown, chestnut above ; lighter, and marked with greyish below. 



Hab. Brazil. 



V. laevis, Isid. Marked as polythrix, but has remarkable proportionate development of wing 

 membranes. 

 Hab. Brazil. 



V. montanus, Philippi and Landbeck. Ears ample, oblong; tragus straight; tail truncated; 

 above mouse color, beneath greyish white ; face above black. Stands between velalus and chilocnsis 

 Hab. Cordilleras at Santiago, 7000 feet above the sea. 



[Aug. 



