330 bulletin: museum of comparative zoology. 



Scotoecus hindei Thomas. 



Scotoecus hindei Thomas, Ann. Mag. Nat. Hist., 1901, ser. 7, 7, p. 264. 



The type of this little-known species was taken at Kitui, British 

 East Africa, 3,500 feet altitude. What appears to be the third re- 

 corded specimen is an adult male collected August 2, 1909, by our 

 expedition. It was found under a loose flake of bark on a large tree 

 growing by the bank of the Guaso Nyiro a few miles above its junction 

 with the Meru River, a small stream which, like the former flows 

 through a semi-desert country. The specimen (no. 8870) agrees in 

 all essential respects with the description of S. hindei, except that on 

 each side of the upper jaw there are two premolars instead of the 

 single large p 4 typically present in the genus. The extra tooth is a 

 very minute spicule, visible only with a hand lens, and is crowded 

 into the internal angle between the canine and the large premolar. 

 Its height is less than that of the cingulum of the adjacent teeth, and 

 it must have been practically functionless. Wroughton (Mem. and 

 Proc. Manchester Lit. and Phil. Soc, 1907, pt. 2, no. 5, p. 4) has 

 recorded the second known specimen of this species. It was taken 

 far to the south of the type locality, at Petauke, Rhodesia. This 

 specimen likewise had a minute second premolar in the upper jaw, 

 described as " fitting into a notch in the inner side of the cingulum of 

 the canine." A similar notch is said to be present in the type, but 

 there is no trace of the minute premolar, nor is there either tooth or 

 notch in the known examples of S. albofuscus and S. hirundo. In our 

 specimen of S. hindei there is no notch in the canine for the reception 

 of the minute premolar. In a fourth species of the genus, S. albigula, 

 recently described from Mt. Elgon by Thomas (Ann. Mag. Nat. Hist., 

 1909, ser. 8, 4, p. 544) this minute tooth, considered by Thomas to be 

 p 1 , is present on either side, in or close behind a deep notch in the 

 cingulum of the canine. 



The genus Scotoecus is doubtless in process of losing the first pre- 

 molar and those specimens in which it is lacking are to be looked on as 

 progressive variations in which it has dropped out altogether. This 

 tendency to condensation of the molar series is found in many bats, 

 and is seen for example, in an interesting specimen of the red bat, 

 Nycteris [= Lasiurus] borealis, no. 9736, M. C. Z., from Martha's 

 Vineyard, Massachusetts. In the skull the small anterior premolars 

 are absent on each side of the upper jaw, and the large p 4 quite fills 

 the space between canine and molars. It represents a progressive 



