304 COUES, BIRDS OF NEW ENGLAND. 



Puffinus Anglorum Temm. Mank's Shearwater. Of 

 not uncommon occurrence off the coast, chiefly in winter. 

 (Omitted from Sam., 0. O.) 



Puffinus fuliginosus Strickl. Sooty Shearwater. 

 "Black Hagdon." Common off the coast, except in sum- 

 mer. (Omitted from /Sam., 0. 0.) 



The whole group of the dusky unicolor Petrels are cer- 

 tainly foremost among the " opprobria ornithologies ; " 

 remaining a standing rebuke that at this late date so little 

 should be accurately known concerning tham. The ques- 

 tion whether this, and certain other birds composing the 

 genus JVectris of Forster, as amended by Bonaparte, are 

 valid species, or only seasonal or sexual conditions of the 

 bicolor Puffini, is still agitated. There cannot be the 

 slightest doubt that there are species of Petrels remain- 

 ing uniformly dusky all through their lives ; e. g. P. 

 sphenurus Gould, P. carneipes Gould, ^Estrelata fuligin- 

 osa Coues ex Kuhl, Majaqueus cequinoctialis Bon. ex 

 Linn., etc. But that certain of the Puffini do not at 

 some period during their progress towards maturity, or 

 afterwards, at some seasons, pass through or acquire a 

 dusky state of plumage, is by no means incontrovertibly 

 proven. For example, I have a strong suspicion that the 

 specimen upon which I based my Puffinus creatopus 

 (Pr. A. N. S. Phila., 1864, p. 131), a bicolor individual, 

 was, a few months before its death, in a uniformly fulig- 

 inous state of plumage. Argument from analogy is 

 readily forthcoming. Witness the well-known immature 

 states of plumage of ^Estrelata Lessonii, ^E. Cookii, ^E. 

 mollis, Ossifraga gigantea, Diomedea exulans, etc., etc., 

 of the Procellariidae ; or, in another family, the species of 

 Stercorarius ; all of which species pass through, or 

 acquire at times, different plumages, one of which is fulig- 

 inous. Let one attempt to study Procellariidce, and he 

 will find, amid a few pretty definitely ascertained facts, 

 an immense mass of heterogeneous, indigestible data, 

 affording ample ground for speculative hypotheses, which 

 are incapable alike of proof or denial, since the key-note 

 whereby they may be harmonized has not as yet been 

 struck. 



