232 Zoological Society. 



evident that inflation by the humerus could not have filled it except 

 through the medium of the lungs themselves. We next proceeded 

 to detach the integument from this air-cell to see its shape and ex- 

 tent ; this required to be done with great care, as it adhered pretty 

 closel}' to the skin and roots of the feathers : it was of a globular 

 form, about four inches in diameter, and communicated with the 

 thorax at its anterior aperture below the trachea. 



" Numerous strips of muscular fibres passed from various parts 

 of the surface of the body, and were firmly attached to the skin ; a 

 beautiful fan-shaped muscle was also spread over the external sur- 

 face of the air-cell anterior to the os ^furciforme. The use of these 

 muscles appeared to be, to produce instantaneous expulsion of the 

 air from these external cells, and by thus increasing the specific 

 gravity of the bird to enable it to descend with the rapidity neces- 

 sary to the capture of a living prey while swimming near the surface 

 of the water. 



" With respect to the general anatomy of this bird, it may be 

 observed that we found the two small glands at the termination of 

 the trachea, which are noticed by Montagu, and which exist in ad- 

 dition to the ordinary pair lying above the hronchice. The stomach 

 corresponded exactly with the figure given by Sir Everard Home 

 (Comp. Anat. pi. xlvi.), the pyloric orifice being provided with the 

 bilobed valve which is there represented, though not described in 

 the text ; it evidently opposes a too ready egress of the contents 

 of the stomach." 



Mr. Vigors exhibited a collection of African Birds which had 

 been presented to the Society by Henry Ellis, Esq., of Portland 

 Place. They consisted of about one hundred and thirty species, 

 many ot them of extreme rarity and value, and a great portion un- 

 known to the cabinets of England. They came immediately from 

 Algoa Bay ; but were supposed to have been collected far in the 

 interior of the country. Mr. Vigors expressed his intention of lay- 

 ing before the Committee at an early Meeting, a descriptive cata- 

 logue of the whole collection, as well as whatever particulars he could 

 collect respecting the locality from w hich it was brought. He named 

 and characterized in the mean time the following apparent novelties 

 from the Insessorial Birds. 



TuRDUS GUTTATUS. TuTcl. supeme olivascenti-brunneus, subtiis sub- 

 Tufescenii-albidus ; strigis tribus genarurn, guttis rotundis pectoris 

 abdotninisque, tectricumque alarum notis brunnescenli-atris ; tec- 

 tricibus alarum, rectrkibusque tribus utrinque lateralibus ad apicein 

 albo notatis. 

 Statura paulo minor quam Turdi iliaci, Linn. 

 Pyurhula albifrons. Pyrr. nigra, capite nuchdquejerrugineo 



nitore subtinctis ; fronte maculdque remigum albis. 

 Longitudo corporis, 7f ; alee, 4 ,; caudce, 3 ; tarsi, f ; rostri, f , 



altitudo f . 

 Ploceus gutturalis. Ploc. supra paUide olivaceo-brunyieus ; 

 capite colloque in fronte aurantiacis, corporc subtus atirantiaco- 

 Jlavo ; guld juguloque nigris, rostra attenuatiore. 

 Longitudo corporis, 6^. 



Ploceus 



