Letters, Extracts, Notices, ^c. 4,77 



Another specimen, lately received at the Academy of 

 Natural Sciences of Philadelphia from the interior of Briti^h 

 Guiana, extends the range of the species very materially. 

 Being interested in looking up the history of this little- 

 known bird, I wrote to Dr. P. L. Sclater to ascertain 

 whether any specimens had reached the British Museum 

 since the publication of the nineteenth volume of the Cata- 

 logue. I was pleased to learn from him that one specimen 

 from Aruwai, interior of Briti>h Guiana, had been obtained 

 by the well-known collector Whitely on June 24<, 1889. 

 Cabanis's original specimen came from Cantagallo, Province 

 of llio, Brazil. The species has evidently a wide range, 

 though apparently very scarce. — Witmer Stone, Acad. 

 Nat. Sci., Philadelpbia. 



Quintocubitalism. — On this difhcult point in the con- 

 struction of the bird's wing two important communications 

 were made to the Linnean Society on the 16th of March 

 last, when Mr. P. Chalmers Mitchell, F.L.S., read a paper 

 on so-called " quintocubitalism " in the wing of birds, lie 

 showed that the terms " aquintocubital " and " quiuto- 

 cubital," applied to birds because of certain conditions in 

 the wings, were misleading, and proposed the new terms 

 " diastataxy " and " eutaxy." Although the Cohim/jce are 

 stated to be a diastataxic group, he remarked that ''eutaxy^' 

 occurs in seven species, and that intermediate conditions 

 exist, which suggested the probability that '^ eutaxy " is a 

 secondary condition produced by the closing up of the gap 

 in the distataxic form. From general considerations based 

 on the anatomy and osteology of Columba, he concluded 

 that the eutaxic forms were clearly more highly specialized 

 and that they had been derived from diastataxic forms. 

 Comparative anatomy making it exceedingly probable that 

 " diastataxy '"'' is the primitive condition among birds, 

 Mr. Mitchell proceeded to show that the primitive existence 

 of a gap was not difficult to explain. In the case of the 

 scales on the feet of birds, and on the limbs and digits of 

 reptiles, a general arrangement was the distribution in 



SER. VII. VOL. V. 2 k 



