154 PROCEEDINGS OF THE ACADEMY OF 



wing. The front, the lores, the sides of the head nearly to the eyes; the 

 side of the neck, and the whole under plumage, pure white. The color of the 

 hack almost always, to some degree, clouds the sides of the breast. 



The above is the plumage of a very mature biid. Usually the plumage is 

 rather as follows. The upper parts generally are less decidedly cinereous — 

 having more of an admixture of brownish — though the upper tail coverts are 

 quite notably plumbeous. The forehead is speckled v/ith black : sometimes 

 the latter color bt-ing in excels over the white. The sides of the breast are 

 very strongly cl)udfd with dark cinereous gray, which may reach quite to 

 the median line ; though this color is only a wash on the extremities of the 

 feathers. Some of the featluTs on the flanks, and a few of the under tail 

 coverts are also lightlj'- touched with plumbeous gray. 



Young. The upper parts show scarcely a trace of cinereous anywhere, 

 except, perhaps, on the upper tail coverts. The front is so much obscured 

 by dusky that the wliite only appears in small sparse specks. The whole 

 under parts are tinged with a plumbeous black hue from the breast back- 

 wards ; this color being deepest on the breast where it is pure and uninter- 

 rupted ; on other parts appearing as a clouding ©r marbling. The chin and 

 throat in all the specimens I have seen remain almost pure white, in marked 

 contrast to the rest of the under parts. The under wing coverts are as de- 

 scribed in the adult: and the white line along the edge of the fore arm also 

 exists. 



It will be noted that the changes of plumage above described are quite 

 homologous with those to which mollis is subject. 



The bill is black. S mewhat more than half the inner web, and rather less 

 than half the outer web, together with the tarsus, are light flesh color. The 

 rest of the toes and webs are black. The colors of the bill and feet seem 

 subject to little variation with age. 



Si/ II on •/ma. The name C ■okii of Gray has priority by about a year over 

 li'iioptrra of Gould ; as, indeed, the latter author himself allows. That 

 these two names were based upon the same species is not doubted, so far as I 

 can learn, except by one author. Bonaparte would have it that the bird 

 figured in plate 51 of the Birds of Australia, and called " Cookii Gray " by 

 Mr. Gould, is not the species really so named by Mr. Gray ; but another ; 

 differing slightly in size, though quite identical in color, and for which he 

 adopts the name velox. In this conclusion, he is quite unsustained by orni- 

 thologists. 



The specimen collected by Mr. T. R. Peale, now before me, which doubtless 

 is the type of his brevipes of 1848, is an example of tliis species. 



This little species is liable to be confounded witli no other, except, perhaps, 

 the succeeding one ; under the head of which latter the apparent difi"erences 

 are noticed. I find no names of the older writers which seem referrible to 

 this species ; and its synonymy is less confused than that of most other 

 components of the genus. 



iEsTRELATA GAVIA (ForSt.) 



ProceUaria gavia, Forst. Descr. Anim. Ed. Licht., 1844, p. 148. ("P. supra 



ccerulescenti-nigra, subtus Candida, palato et lingua villis deflexis, 



pedibus palliile-fuscis. * * Habitat ad iEstuarium Reginje Char- 



loltie. * * Corpus magnitudine circiter P. vittatie. * * Alae 



expansse 26 unc. rostrum in fronte 1-50; tibire 1'75 ; cauda 2-50." 



Forst.) G. R. Gray, Voy. Ereb. and Terr. Birds, pt. x. Oct., 1845, 



p. 18. — Id. Ibis, 1862, iv. p. 246. From Queen Charlotte's Sound. 



This is a species which is not recognized, and, in fact, does not appear to 



he noticed in later systematic works. In addition to the diagnostic points 



quoted above, Forster describes it as having the pileum, neck behind, back, 



rump, thighs, tail, and upper surface of the wings, bluish black ; the chin, 



[May, 



