214 



CHIROPTEEA 



tendency away from the cinnamon and raw-umber tints toward 

 a clearer brown more resembling Ridgway's mars-brown. Mem- 

 branes less blackish than in P. pipistrellus, the wing from foot 

 nearly to fifth finger with a noticeable pale border about 1 mm. 

 in width, similar to that present in P. huhlii, but less sharply 

 denned and less nearly white. 



Skull. — The skull is less diminutive than that of Pipistrellus 

 pipistrellus, its general size about as Myotis mystacinus. General 

 form less robust than in P. pipistrellus, the width of brain-case 

 barely one-half greatest length, but more contrasted with that of 

 rostrum. Dorsal profile as in the smaller species, but with more 

 evident anterior concavity and posterior convexity, the anterior 

 edge of interparietal indicated by a slight transverse constriction. 

 Other details of form essentially as in P. pipistrellus. 



Teeth. — As compared with those of Pipistrellus pipistrellus the 

 teeth throughout show a tendency toward slenderness and height. 

 Inner upper incisor noticeably more slender than that of P. 

 pipistrellus, and with less well developed secondary cuspj outer 

 upper incisor distinctly larger than inner, its apex extending 

 noticeably beyond secondary cusp of inner tooth, its general form 

 essentially as in P. pipistrellus, but inner margin without evident 

 secondary cusp. Lower incisors less crowded than in P. pipis- 

 trellus, a slight space usually present in 

 median line, another between i 2 and i s , and 

 another between i s and canine ; outer edge 

 of i x slightly overlapping « 2 ; in form the 

 teeth are not peculiar. Upper canine like 

 that of P. pipistrellus, except that the 

 greatest diameter of its crown is only about 

 half length of anterior border of shaft. 

 Fig. 36. Mandibular canine high and slender, its apex 



Pipistrellus nathusii. rising distinctly above that of highest molar 

 Anterior teeth x 5. cusps, its greatest diameter measured along 

 cingulum equal to a little more than half 

 length of anterior border ; apex of anterior cingulum cusp not 

 rising above level of basal third of posterior border. Upper 

 premolars as in P. pipistrellus, except that the small tooth is 

 relatively higher and more perfectly in the tooth-row, and the 

 posterior border of its shaft usually shows some indication of an 

 angular secondary cusp corresponding to that of canine. Lower 

 premolars with crown area more nearly equal than in the 

 smaller species, but without special peculiarities of form. Molars 

 both above and below essentially similar to those of P. pipistrellus. 

 Measurements. — Adult male from Berlin, Germany (topotype) : 

 head and body, 45 ; tail, 35-4 ; tibia, 13 ; foot, 6'8 ; forearm, 

 33; thumb, 5-2; third finger, 65; fifth finger, 47; ear from 

 meatus, 1 2 ; width of ear, 1 1 . Average and extremes of six 

 adults from Buchillon, Vaud, Switzerland : tibia, 1 2 • 9 ( 1 2 • 6-1 4) ; 

 foot, 7-3 (6-8-7-6); forearm, 33 (32-4-34-6); thumb, 5-7 



