﻿MYOTIS VELIFER. 



57 



General characters. — Largest species of Myotic known to occur in 

 Mexico or the United States. Length 90 to 105, forearm 40 to 47. 

 Calcar slender, without well-developed lobe. Free border of uropata- 

 gium naked. Ears short, reaching tip of nose. Wings from metatarsus. 



Ears. — The ears are short and pointed ; laid forward they reach to or 

 just beyond nostril. Auricle concave on botli sides immediately below 

 the narrowly rounded o^' tq) (most strongly so on the posterior border). 

 Anterior border straight or very slightly convex through the basal two- 

 thirds of its length, then concave or almost straight to tip; i^osterior 

 border strongly concave directly below tip, then still more strongly con- 

 vex to basal notch, tlie widest part of the ear at about mid height. Basal 

 notch well defined, isolating a prominent basal lobe, which is slightly 

 notched on the lower side and joins tlie side of the face in a line which 

 if continued would coincide with the margin of the upper lip. 



Tragus moderately long and broad, the anterior ( dge straight or very 

 slightly convex toward the tip; posterior border with a well-developed 

 lobe at base; just above the lobe the tragus attains its greatest width; 

 the two borders are usually parallel for a short distance, after which 

 tlie posterior border bends rai)idly forward to the tip, below which it 

 may be either straight or very slightly concave. 



Membranes. — The membranes are, for an American Myotis, rather 

 thick and opaque. The uropatagium is sjiarsely haired both dor- 

 sally and ventrally on its j^roximal fourth; the free border, which is 

 distinctly shorter than the calcar, wholly naked. Wing from point 

 between ankle and base of toes, but nearer the latter. When drawn 

 away i)erpendicularly from the leg, the wing ai^pears to be attached to 

 the ankle. 



Feet. — Feet (PL II, fig. 6) large and strong, half as long as tibiie. Toes 

 (without claws) slightly longer than sole, scarcely united by membrane 

 at extreme base, all sprinkled with long, stiff hairs. Calcar long, slen- 

 der, usually terminating indistinctly, but sometimes with a more or less 

 well defined lobule at tip. 



Fur and color. — There is nothing peculiar about the distribution of 

 the fur to distinguish this bat from other American members of the 

 genus. 



In color the fur is dull sepia throughout, paler on the belly, the hairs 

 everywhere dusky slate at base. Individual variation is trifling and 

 is mostly confined to the belly. This is usually dull broccoli brown, 

 but in some specimens by admixture of yellow it becomes more nearly 

 Isabella color. 



SliUll. — Skull stronger and more heavily built than in any other 

 Myotis found in Mexico or the United States, but not actually larger 

 than that of M. thysanodes. Greatest length (5 specimens) 16 to 16.4; 

 zygomatic breadth, 10 to 11; interorbital constriction, 4 to 4.2; width 

 of rostrum at anterior root of rnl, 6 to 6.2; length of mandible, 12 to 

 13. When viewed from above, the brain case is subcircular in outline 



