Miller Second Collection of Bats from Curasao, 161 



Character*. Externally similar to Mexican specimens of Natalus 

 stramineu* Gray, but fingers shorter and ears somewhat more pointed. 

 Skull with braincase more abruptly elevated than in the Mexican 

 species, and rostrum conspicuously inflated at sides. Teeth throughout 

 larger than in N. stramineus, the lower premolars noticeably broadened. 



Color. Dorsal surface uniform cream-buff, the tips of the hairs grad 

 ually darkening to pale drab; belly similar, but the buff slightly more 

 tinged with yellow and the drab less apparent. Ears and membranes 

 light brown. 



Ears. The ear is essentially as in N. *tram$neu8fb\Lt the point is dis 

 tinctly longer and narrower. 



Membranes, feet, and other external characters as in N. stramineus. 



Skull. Though in general appearance, the skull of Natalus tumidiros- 

 tris resembles that'of N. stramineus it is immediately distinguishable by 

 the conspicuously swollen sides of the rostrum. The inflation involves 

 the maxillary bones from anterior edge of orbit almost to nares, and 

 from near edge of toothrow to nasals. As the nasals retain the normal 

 form they appear to occupy the floor of a broad, shallow, longitudinal 

 groove. In the type the braincase rises above the dorsal plane of the 

 rostrum at an angle of 50, in a second specimen at an angle of 58. In 

 two specimens of N. stramineus the angle is respectively 34 and 40. In 

 both specimens of Natalus tumidirostris the bony palate terminates on 

 each side at the plane of the postero-internal angle of the crown of the 

 second molar. In the median line it is continued slightly further back 

 along palatal face of vomer. The resulting form is strikingly different 

 from that of the palate in other members of the genus. It is possible, 

 however, that the palate is normal and that its peculiarity in the two 

 specimens is the result of injury. As both skulls were cleaned by an 

 experienced preparator there seems little probability that the palate was 

 originally of the usual form. 



Teeth. The dentition is throughout heavier than in N. stramineus, 

 and the form of the individual teeth differs in many important details. 

 Canines and incisors as in N. stramineus. Relative size of upper pre 

 molars as in N. stramineus, that is the crown area decreasing regularly 

 from third to first, the latter equal to about one-half former, but cusp 

 of first slightly longer than that of second. In each tooth the transverse 

 diameter is greater relatively to the longitudinal diameter than in 

 the Mexican animal. Upper molars broader than in N. stramineus, the 

 posterior commissure of protocone of first and second distinctly marked 

 by a rudimentary hypocone. The lower premolars and molars differ from 

 those^of N. stramineus in greater breadth of crown, this character 

 especially noticeable in the second and third premolars. 



Measurements. External measurements of type ((J) and paratype (?): 

 total length, <$ 96, 9 94; tail, $ 47, 9 45; tibia, $ 18.4, 9 17.6; foot, 

 cf 7, 98; forearm, ^ :: 36, 9 35; thumb, cT 5, 9 4.8; second digit, $ 

 35, 9 35; third digit, J 72, 9 69; fourth digit, $ 52, 9 50; fifth dig-it, 

 $ 51, 9 49;, ear from meatus, $ 15.4, 9 15.4; ear from crown <J 11.4, 

 9 12. 



