1902.] NATURAL SCIENCES OF PHILADELPHIA. 403 



At San Bias Chilonycteris mexicana was very coniinou iu a small 

 uari-ow cave which exteuded like a deep crevice iuto the base of the 

 cliff on the hillside facing the town. 



Mormoops tumidiceps sp. nov. 



Type. — Adult male (in alcohol), No. 5,o81, collection of Dr. C. 

 Hart Merriam. Collected in the Point Gourde Caves, Trinidad, 

 1889, by Sir William Robinson. 



Characters. — Externally similar to Mormoops megalophylla; skull 

 larger and more swollen than that of the ^lexican animal. 



Color and other External Features. —After many years' immer- 

 sion in alcohol the specimen presents no external characters to dis- 

 tinguish it from Mormoops megalophylla. 



Skull and Teeth. — The skull differs from that of Mormoops 

 megalophylla in greater size, due to increased breadth of both ros- 

 trum and braincase, though particularly of the latter. There is no 

 other evident difference in form. Teeth as in M. megaloj)hylla 

 except that the premolars both above and below are slightly larger, 

 a difference which may readily prove to be no more than indi- 

 vidual. 



Measurements. — External measurements of type: Total length, 

 92; tail, 26; tibia, 22; foot, 11 (10.4); forearm, 55; thumb, 7; 

 second digit, 50; third digit, 102; fourth digit, 73; fifth digit, 

 65 ; ear from meatus, 14 ; ear from crown, 8. 



Cranial measurements of type: Greatest length, 15 (14.(5) ;'■ basal 

 length, 15 (14.6); basilar length, 13.2 (13); median palatal 

 length, 8.6 (8.4); least interorbital breadth, 5.6 (5); lachrymal 

 bi-eadth, 7.4 (7); zygomatic breadth, 9.8 (9.2); mastoid breadth, 

 9.2 (8.6); greatest breadth of braincase, 10 (8.8); mandible, 13 

 (12.8); maxillary toothrow (exclusive of incisors), 8.2(8); 

 mandibular toothrow (exclusive of incisors), 8.8 (8.4). 



Specimens Examined. — One, the type. 



Remarks. — The differences between Monnoops megalophylla and 

 M. tumidiceps are of the same kind and extent as those separating 

 Natalus mexicanus from N. stramineus and Chilonycteris mexicana 

 from C. rubiginosa. The Trinidad Mormoops is very different 

 from the small M. intermedium of Cui'ayao. 



1* Measurements in parentheses are tliose of an adult male Mormoops 

 megalophylla from Tampico, Mexico (No. 60,378). 



