254 



CHIEOPTEEA 



NYCTALUS AZOREUM Thomas. 



1901. Pterygistes azoreum Thomas, Ann. and Mag. Nat. Hist., 7th ser., vm, 

 p. 33, July, 1901. Type in British Museum. 



Type locality. — St. Michael, Azores. 



Geographical description. — Azores. 



Diagnosis. — Smaller than Nyctalus leisleri (condylobasal length 

 of skull, 13 to 14 • 2 mm. ; forearm, 35 to 42 mm.) ; colour darker 

 than in the Continental European species. 



External characters. — Except for its conspicuously smaller 

 size Nyctalus azoreum does not differ appreciably in external 

 features from N. noctula. The fifth finger shows a tendency to 

 be less shortened relatively to length of forearm, but this is appa- 

 rently not constant enough to be regarded as a specific character. 



Colour. — Upper parts prout-brown, the hairs with darker, 

 ill-defined slaty basal area, and usually with lighter tips, the 

 lighter colour ranging in different individuals from raw-umber 

 through wood-brown to a dull light buff, and usually producing 

 a noticeable wash from shoulders backward, particularly near 

 edge of membranes ; underparts not essentially different from 

 back ; muzzle, cheeks, ears, and wings blackish. 



Shull and teeth. — The skull does not differ appreciably in form 

 from that of N. noctula, though it is perhaps slightly narrower 

 and deeper, and the surface is more smoothly rounded off; 

 lambdoid crest slightly developed. Teeth essentially as in the 

 larger species, but transverse diameter of m 3 relatively greater, 

 crown area of upper incisors nearly equal, and lower incisor row 

 forming a more abrupt convexity. 



Measurements. — Type (adult male, St. Michael) : head and 

 body, 54 • tail, 42 ; tibia, 17 ; foot, 7 ■ 7 ; forearm, 37 ; thumb, 6 ; 

 third finger, 62 ; fifth finger, 43 • 7 ; ear from meatus, 12. Adult 

 male from Terceira : head and body, 50 ; tail, 43 ; tibia, 16 ■ 6 ; 

 foot, 7 ; forearm, 42 ; thumb, 6 ; third finger, 72 ; fifth finger, 

 48 ; ear from meatus, 12 ; width of ear, 11. For cranial measure- 

 ments see Table, p. 255. 



Specimens examined. — Seventeen, from the following localities in the 

 Azores : — Teroeira, i (B.M. and U.S.N.M.) ; above Magdalena, Pico, 5 ; St. 

 Michael, 6 (B.M. and U.S.N.M.) ; St. George, 2. 



Remarks. — The Azorean Nyctalus is slightly more differentiated 

 from N. leisleri than the Continental forms are among themselves, 

 since it differs from the other members of the genus rather 

 noticeably in colour as well as in size. The specimens show 

 considerable variation in the extent of the light wash on upper 

 parts caused by the pale tips to the longer hairs, but this appears 

 to be independent of locality. 



<5 al. St. Michael, Azores. F. Du Cane Godman 65. 10. 2. 1. 



(o & p). (Type of species.) 

 2(5,2?. St. Michael. (W. B. 0. Hon. W. Eothschild 3.6.5.1-3,7. 

 Chant.) (p). 



