194 



CHIROPTERA 



conch, its greatest width (slightly above level of anterior base; 

 contained about 2^ times in length of anterior margin, the 

 posterior border conA^ex to just below rather bluntly rounded tip, 

 the anterior margin straight, posterior basal lobe small but well 

 developed ; inner surface of conch with seven or eight ill-defined 

 transverse ridges near posterior border. Wing rather broad but 

 with no special })eculiarities of form ; metacarpals somewhat 

 elongated relatively to phalanges as compared with the smaller 

 species, the third, fourth and fifth slightly but evidently 

 graduated, the third scarcely shorter than forearm ; membrane 

 inserted at side of metatarsus, but with a narrow strip extending 

 to base of outer toe as in M. natter eri. Foot slightly more than 

 half as long as tibia ; calcar heavy at base but tapering rapidly 

 and terminating obscurely, its posterior border with slightly 

 indicated keel, its length about equal to that of free border of 

 interfemoral membrane. Tail about as long as body without 

 head, only the extreme cartilaginous tip free from membrane. 



Fur and colour. — Relatively to size of animal the fur is rather 

 short (longest hairs of back about 10 mm.); in distribution it 

 shows no peculiarities ; free border of uropatagium without 

 fringe. Colour an indefinite brown much like that of Myotis 

 nattereri, the exact shade intermediate between the wood-brown 

 and broccoli-brown of Ridgway, usually paler on head and neck 

 than on back, and in immature individuals than in adults, the 

 hairs slate-black through basal half, then light wood-brown 

 followed by a darker though not strongly contrasted terminal 

 area. Underparts strongly contrasted greyish white with a 



slight buffy tinge ; a well-defined 

 line of demarcation along sides 

 of neck to ear, emphasized in 

 region of shoulder by a slight, 

 diffused blackening of edge of 

 dark area. Muzzle and cheeks 

 dusky. Ears and membranes an 

 indefinite brown. 



Skull. — Though much larger 

 than that of any of the other 

 European species of Myotis, M. 

 oxygnathus excepted, the skull of 

 Myotis myotis is one of the most 

 slender in general outline. The 

 brain-case is longer proportion- 

 ately to its breadth and is less 

 contrasted with rostrum than in 

 the small members of the group ; 

 greatest breadth of brain-case 

 about one-half distance from 

 lambda to posterior margin of nares. Rostrum relatively deej? 

 and interorbital concavity relatively shallow ; occipital region 



riG. 32. 

 Myotis myotis. Nat. size. 



