1918 | Grinnell: A Synopsis of the Bats of California 371 
Description—Head elongate (length of head, in alcoholic speci- 
men, 42 millimeters, greatest width, 20); muzzle pad prominent, 
deeply emarginated above, its upper edge and median ridge with 
minute horny processes and small spoon-hairs; nostrils large, directed 
downward and outward; eyes placed far back on sides of head (center 
of eye, in alcoholic specimen, 21 millimeters from tip of muzzle), and 
almost concealed by the drooping anterior border of the auricle. In 
front of each eye is a prominent glandular swelling. Ears large, 
directed outward and forward, joined in median line, and so large as 
to entirely conceal face and muzzle from an observer when viewing the 
bat from the dorsal side. Ear conch, or auricle, broadly convex anter- 
iorly and posteriorly, slightly convex on top (pl. 20, fig. 21). Tragus 
small, truncate (in aleohohe specimen 3.5 millimeters in height at 
anterior edge and 3 millimeters in breadth at top), and nearly con- 
cealed by the semi-oval antitragus, which is (in alcoholic specimen) 
10.5 millimeters in length and 7 in greatest height; antitragus sep- 
arated posteriorly from conch by a deep notch. Ears haired along 
margin, but greater portion of keel, both externally and internally, 
naked. Folds of ears directly above nostrils heavily haired on both 
upper and lower surfaces. Upper lp with a thick fringe of down- 
ward-direeted hairs. 
Limbs and Membranes.—Wings long and slender (pl. 19); fifth 
metacarpal scarcely more than half length of third. Dorsal surface 
of wing membrane, as well as interfemoral membrane, furred to a 
distance of about 12 millimeters from body. A small patch of hairs 
on dorsal surface of antebrachial membrane, this patch extending 
inward from edge of radius, except at bottom of angle formed by 
junction of radius with humerus; another group of hairs extending 
along distal three-fourths of posterior edge of forearm, widening and 
occupying angle between forearm and fourth metacarpal; a third 
small group of hairs at distal end of third metacarpal. A small patch 
of fur on ventral surface of antebrachial membrane, occupying angle 
between anterior edge of membrane and proximal half of humerus; 
a line of fur extends from this patch across humerus and along its 
posterior edge and unites with a small patch on lateral. membrane 
immediately posterior to distal end of humerus. Interfemoral mem- 
brane not haired, except for a narrow border along proximal margin 
of its dorsal surface, and a few scattering hairs along edge of post- 
ealearial lobe. Legs and feet short and stout; feet only twice as 
long as wide. 
Pelage—F ur long and soft, denser and shorter on abdomen than 
elsewhere, varying in length from 5 to 10 millimeters. 
Color—Membranes deep hair brown; fur a lhghter tone of same 
color, slightly paler on ventral surface; bases of hairs everywhere 
whitish for a distance of from one-half to three-fourths their length. 
Skull and Teeth.—As given for the genus (see p. 370). 
Measurements.—Average and extreme measurements in milli- 
meters of ten specimens of the mastiff bat in the Museum of 
Vertebrate Zoology are as follows: total length, 167.1 (extremes, 
157.0-184.0) ; tail vertebrae, 59.7 (52.0-70.0) ; tibia, 22.1 (21.0-23.3) ; 
foot, 16.8 (13.0-19.0) ; forearm, 72.0 (69.0-74.5) ; greatest length of 
cranium, 31.0 (30.0-32.0). Five specimens, measured fresh, showed 
