Zoological Society. 527 



" Subsequently I have mentioned, in the ' Appendix to Gerber's 

 Anatomy,' that the corpuscles of Birds may present, comparatively, 

 either the figure of a very broad or of a very narrow ellipse. Of the 

 latter shape, examples may be found in the corpuscles of the Great 

 Butcher Bird (Laniiis excubitor), Nightingale {Philomela biscinici), 

 Snow Bunting {Plectrophanes nivalis) ; and of the former shape in 

 the corpuscles of the Java Sparrow {Loxia Javensis), and several 

 other granivorous birds. 



" The nucleus of the blood-corpuscles of Birds, when exposed by 

 acetic acid, has almost always a more elongated form than the un- 

 changed envelope, as mentioned in the book just quoted. But to 

 this rule I have since found a few remarkable exceptions. In the 

 Common Fowl (Gallus domesticus), for instance, the nucleus is a 

 very short ellipse, and even sometimes nearly or quite circular. For 

 the difference between the shape of the nucleus, when exposed by 

 acetic acid, or by soaking the corpuscles in water, a figure may be 

 consulted which I have given to illustrate this subject in my ' Con- 

 tributions to Minute Anatomy,' Lond, andEdin. Phil. Mag., August 

 1842, imge 109." 



A paper was then read from Mr. Gould, in which he gives the 

 characters of two new genera of Birds, one belonging to the family 

 Sylviadce and the other to the PsittacidcE. 



" Having observed," says Mr. Gould, " during my late visit to 

 Australia, much difference to exist in the habits of the birds usually 

 placed in the genus Platycercus, I was naturally led to investigate 

 the matter as fully as circumstances would admit, and on examina- 

 tion of the two birds known as PI. erytkropterus and PI. scapulatus, 

 I found that the difference of their habits from those of the typical 

 Platycerci was accompanied by a sufficient difference in their ana- 

 tomy to warrant their separation into a distinct genus. Indepen- 

 dently of the variations indicated in the generic characters given 

 below, these birds are remarkable for possessing a tolerably well- 

 developed OS furcatorium, which bone is entirely wanting in the true 

 Platycerci and Eiiphemi : in their habits they approach nearer to the 

 Lories, are of a dull and sullen disposition, and do not readily become 

 tame and familiar like the Platycerci ; they are also essentially arbo- 

 real, procuring their food among the branches of the trees ; while 

 the Platycerci resort to the ground and feed principally upon grass 

 seeds." 



These two birds he therefore proposed to erect into a new genus, 

 under the appellation of 



Aprosmictus. 

 Gen. Char, ut in Platycerco. — Rostrum attamen debilius, ceromate 



plumis tenuibus instar pilorum nares adumbrantibus instructo. 



Al(E longiores et minvis concavse. Cauda magis quadrata. Tarsi 



breviores. Digit i longiores. 

 Types. — Platycercus scapulatus and erythropterus, which will now 



stand as Aprosmictus scapulatus and A. erythropterus. 



The other birds which Mr. Gould proposed to form into a new 



