46 Howell — A New Bat from Nirl:ajarh Cave, Tennessee. 



Myotis grisescens sp. nov. 



GRAY BAT. 

 Myotis relifer Miller, N. Am. Famia, No. 13, p. 59, 1897 (in part; speci- 

 mens from Marble Cave, Mo.); Hahn, Proc. U. S. Nat. Mus. XXXV, 



p. 580, 1908 (Indiana). 



Type from Nickajack Ca\'e, near Shellmonnd, Marion County, Tennes- 

 see. No. 157,517 U. S. National Museum, Biological Survey Collection. 

 <? adult, skin and skull. August 31, 1908. A. H. Howell. Original num- 

 ber, 1233. 



General characters. — Nearest to Myotis velifer, but differing from it 

 in darker color, smaller skull, weaker dentition, and in the point of 

 attachment of the wing membranes to the feet. 



Color. — Varying above from dark hair-brown to dark mouse-gray, the 

 hairs concolor to the roots ; below mouse-gray basally, pale smoke-gray 

 at tips; fianks and posterior border of abdomen paler, the hairs whitish 

 and concolor; ears, feet, and membranes black. 



Skull and teeth. — Compared witli M. velifer, the skull of grisescens 

 shows the following differences : Rostrum shorter aild narrower ; frontal 

 region markedly depressed; parietal region rising more abruptly from the 

 rostrum, thus giving to the skull a "pug-nosed" apiiearance; zygomata 

 more widely expanded; dentition weaker, the upper canines and third 

 upper premolars decidedly smaller; first and second upper molars with 

 hypocone slightly developed (absent in velifer). 



External characters. — The feet are large, as in velifer ; the ears are only 

 a trifle shorter than those of velifer and the tragus is about the same 

 length as in that species. The wings are attached to the feet close to the 

 ankle joint, not at base of toes as in velifer. 



Measurements. — Average of 10 topotypes: Total length, 93;* tail ver- 

 tebrae, 37.5;* extent, 282;* tibia, 17.5; foot, 10.5; forearm, 41.6; longest 

 finger, 70; ear from meatus, 14.5; tragus, 8.8. Skull: Greatest length, 

 15.9 (15.5-16.3); condylo-basal length, 14.9 (14.7-15.1); zygomatic 

 breadth, 9.9 (9.6-10.2) ; breadth of braincase, 8.2 (8-8.4) ; length of upper 

 tootlarow (exclusive of incisors), 5.9 (5.8-6.1); length of mandible, 11.6 

 (11.3-11.8). 



Geographic distribution. — Specimens have been examined as follows: 

 Tennessee : Nickajack Cave, 83 (21 skins). 

 Missouri : Marble Cave, Stone County, 3 (alcoholics). 

 Indiana: Mitchell, 1 (skin).t 



Remarks. — This species, though agreeing rather closely with Myotis 

 velifer in size, difiers from it widely in color, and indeed is quite uidike 

 any other North American bat in this respect. It is the largest member 

 of the genus occurring in the eastern United States and is equaled only by 

 M. velifer, M. incantus, and M. thysanodes of the southwestern States. 



Three specimens in alcohol from Marble Cave, IMissouri, have been in 

 the Biological Survey for some years, but have always been referred to 



* Measured in the flesh ; other measurements from alcoholics. 



+ Collection of the University of Indiana; kindly loaned by Dr. C. H. Eigcnmann. 



