394 ITvOCEEDINGS OF THE ACADEMY OF [May, 



api)ear:iuce may have been slightly altered by drying. It is quite 

 different in form from that of N. europs, and not thickened at the 

 edge as in N. laticaudatus. Antitragus large, in form exactly like 

 that of N. Jemorosaccus, therefore higher in proportion to its width 

 than in N. laticaiulatm and N. europs. Tragus as in iV. femoro- 

 saccus. 



Color. — Dorsal surface uniform vandyke-brown, the hairs whitish 

 at base, but not sharply bicolor. In certain lights the extreme 

 tips of the hairs show a faint wash of wood-brown, and in others 

 there is a strong sheen of bluish ecru-drab. Under parts like 

 back, but strongly tinged with wood-brown. Ears and membranes 

 dark brown. 



Skull. — The skull is intermediate in size between that of Nydi- 

 nomops europs and the larger N, laticaudatus and N. jemorosaccus. 

 In form it shares to a certain extent the shortening of the rostrum 

 that characterizes the Brazilian species, but this peculiarity is not 

 carried as far, nor is the cylindric contour of the interorbital region 

 noticeably impaired. The orifice of the anterior uares is more 

 tul)ular than in N. europs, but less so than in N. Jemorosaccus. 



Teeth. — The teeth agree in all respects with those of Nyctinomops 

 europs except that the upper incisors are larger and more closely set. 



Measurements. — External measurements of type: Total length, 

 98; tail, 42; tibia, 12.4; foot, 9 (7.8); forearm, 42; thumb, 8; 

 second finger, 40 ; third finger, 81 ; fourth finger, 60 ; fifth finger, 

 42; ear from meatus, 15; ear from crown, 11.6; width of ear, 

 17; tragus, 1.8. 



Cranial measurements of type: Greatest length, 17.2 (16.6);^ 

 basal length, 15 (14.8) ; basilar length (to posterior edge of pala- 

 tal emargination), 13 (12.4); interorbital constriction, 3.4 (3.4); 

 zygomatic breadth, 10 (9.4); greatest breadth of braincase above 

 roots of zygomata, 8.8 (8); mandible, 12.4 (11.4); maxillary 

 toothrow (exclusive of incisors), 6.4 (6.2); mandibular toothrow 

 (exclusive of incisors), 7 (6.8).'"' 



Specimens E.vamined. — Twelve, all from the type locality. 



^Measurements in parentheses are those of a paratype of Nyctinomops 

 eicrops (9, No. 101,502). 



*Some of tlie nieusurcnients of a skull of Nyctinomops femorosaccus 

 from Fort Iluachuca, Arizona (No. 36,0:38) are : Greatest length, 19 ; 

 l)asal leng'h. 17 ; zygomatic breadth, 10; maxillary toothrow (exclusive 

 of incisors), 7.G. 



