580 



Comparing Myotis muricola with other bats from the same locality 

 I find no nearer ally — apart from the dental formula — than the afore- 

 mentioned Pipistrellus annectens. As said above the latter is from Su- 

 matra, and according to Dobson's note at the bottom of page 316 also 

 Myotis muricola has been found in the same locality. 



The measures seem to vary in both species. Dobs on states that 

 in Myotis muricola the length of head and body is 1,75 inches (44 mm) 

 and that of the forearm 1,35 inches (33 mm). In the examples of this 

 Institute the length of head and body varies from 38 to 42 mm, and 

 that of the forearm is 35 or 36 mm. 



And Mats chi e 12 says: »Man kann also annehmen, daß die muri- 

 cola der Halmahera-Grvijìiie , wenn sie ausgewachsen sind, eine Unter- 

 armlänge von 37 — 38 mm besitzen.« 



Pipistrellus annectens seems to be represented by two forms: a 

 large continental one described by Dob s on and a small one from the 

 island of Sumatra, of which latter form the collection of the Zootomical 

 Institute has three examples. And there are perhaps transition forms, 

 though, so far as I know, they have not been recorded in the littérature. 



In Myotis myotis Bechstein, of which species I have examined 

 7 specimens, I found that in some specimens the second upper premolar 

 is situated in the tooth-row, in others it is placed inside the tooth-row 

 and more or less distinctly visible from without. 



Instances of individual variation are to be found in several genera 

 and species of bats. 



Lechei^ mentions various bats in which the tendency to lose the 

 above-mentioned and other teeth is stated. He speaks of the reduction 

 of the first upper premolar in most species of the genus Pipistrellus 

 [Vesperugo] which reduction may in single individuals result in the non- 

 function or total absence of this tooth. He mentions an intermediate 

 bat between the genera, Pipistrellus [Vesperugo) OiXià. Eptesicus [Vespe- 

 riis), viz. a specimen of Pipistrellus inaurus, in which the first upper 

 premolar is rudimentary, having hardly cut through the gums. 



In 3 specimens of P. maurus which I have examined the first upper 

 premolar is rather well developed and visible from outside. 



As to Pipistrellus kuhlii and Pipistrellus pipistrellus I have exami- 

 ned 3 skulls and 8 specimens in alcohol of the former and found that in 

 1 example the first upper premolar is rather well developed and visible 



12 P. Matschie, DieSäugetiereder von W. Kükenthal auf Halmahera, Bat- 

 jan und Nord-Celebes gemachten Ausbeute. Abhandlungen d. Senckenberg. Natur- 

 forsch. Gesellschaft XXV. 1901. p. 275. 



13 "W. Lech e , Studier öfver mjölkdentitionen och tändernes homologier hos 

 Chiroptera. Lunds Universitets Arsskrift. Tome XII. 1875. p. 34. 



