of the Genera of Bat. 35 



In a late visit to the College of Surgeons, I was much struck 

 at observing the small size of the wing of the Foetuses oi Pte- 

 ropi, compared with these parts in the adult animal ; and on 

 continuing the examination I found that the same difference of 

 development appeared to take place in the other genera of bats. 



These differences in the relative development of the fore 

 and hind extremities appear to have escaped the observa- 

 tions of Temminck and other modern writers on this family 

 of animals ; it is of the more importance, as several of the 

 writei's on this subject have been induced to place great re- 

 liance on the proportions of these parts compared with the 

 size of the body in their specific descriptions. Indeed, in the 

 last part of the Linnaean Transactions, the Rev. Mr. Jenyns, 

 who is certainly a very acute observer, and who has paid 

 great attention to the bats of this country, has been induced 

 to describe a bat as a distinct species, which only differs in 

 the relative measurement of these parts, under the name of 

 Plecotus brevimamis ; and which from the examination of a 

 specimen in the collection of the Zoological Society, named 

 by the author, I am induced to think is only the very young 

 state of Vcspertilio auritus, as I had named the specimen when 

 I was assisting in making the catalogue of the Mammalia and 

 Reptiles of that collection. 



1 shall give a description of the young state of Pteropns*, 

 as I have been enabled to see thi'ee specimens, in different 

 stages, of an apparently undescribed species, which were dis- 

 covered in the late expedition under Captain Beechy, which 

 I refrain from describing, as Mr. Lane, the naturalist of the 

 expedition, informed me that he intended soon to describe it 

 in another journal. 



The Fcctusoi' the Pteroptis (cut from the body of the mother) 

 has a large head, and small arms: and wings with a large 

 longly clawed thumb. The hind legs and claws are also very 

 large and perfectly formed. These peculiarilic s are easily ac- 

 counted for when the habits of the young bat are considered ; 

 for in the young state they do not require the use of their 

 wings, but rest attached to the sides of their mother, and for 

 the pui-jiose of holding themselves on, they are provided with 

 large and well-clawed thumbs and feet, allowing the wings to 

 gradually develope themselves. 



In a visit which I lately paid to Ilaslar Hospital, at Ports- 

 mouth, for the purpose of examining the Mollusca brought 

 home, and so well described by the collector, the suigcoii 

 of the expedition, I was f<jrtunate enough to discover a very 



* Plcmpm psc/fi/i/ioii, Lay, Zool. Jour. vol. iv, j-. l.'>7. 



Y 2 Vdiiiig 



