Si PROCEEDINGS OF THE ACADEMY OF 



branes, so conspicuous in oceanica. The most important difference in form 

 between the two species lies in the much greater flatness and obtuseness of 

 the claws of lineata. 



With the following two species I am autoptically unacquainted, and can 

 only judge of their specific validity, and of their generic relations, from the 

 descriptions of their authors. They evidently, however, belong to the long- 

 legged, depressed-clawed group of Stormy Petrel, and I think there can be 

 little or no doubt that they both are species of Oceanites. Such indeed is 

 certainly the case with the Thai, segethi of Phillippi and Landbeck,* the de- 

 scription of which is so complete and perfect in every respect, that I have no 

 difficulty in assigning it to its proper genus. Would that all birds could be 

 as thoroughly described on their first introduction to ornithologists! The 

 Thai, gracilis, Elliot, seems so closely allied to both lineata and segethi, that it 

 can hardly but be an Oceanites] though I cannot speak concerning it with the 

 same degree of certainty as I do regarding the former species. 



3. Oceanites segethi, Coues. ex Ph. et Ldbk. 



Thalassidroma segethi, Phillippi and Landbeck, Wiegmann's Archiv, 1860, p. 

 282. The following description of this species is condensed from the one 

 originally given by its discoverers : 



The bill and feet are glossy black. The head, neck, back, throat and breast, 

 as well as the upper wing coverts, dark blackish gray, the latter, however, 

 tending somewhat towards brownish. Wing and tail feathers deep black. 

 The feathers of the upper parts have white borders, which, however, are 

 worn away in the course of the summer. The inner web of the four outer 

 tail feathers is white at the base. The upper tail coverts, the abdomen, the 

 flanks, and the circumanal region are white. Under tail coverts are black, 

 with white bases and tips. The lesser inferior wing coverts, and the whole 

 border of the wings are black, the rest of the inferior coverts white. 



Length 1\ inches (French). Bill 6 lines ; tail 2 inches 11 lines ; wing 5 

 inches. Tarsus 1 inch 5 lines ; middle toe 10 lines. Naked portion of the 

 tibiae 7 lines: Wings when folded reaching an inch beyond the tail. 

 Habitat. The coast of Chili. 



This species is compared by its describers with the lineata as follows : " It 

 comes nearest to the species described by Titian Peale, in the United States 

 Exploring Expedition, which was found breeding on the Island of Upolu. 

 This species agrees with ours in size, in the form of the feet, and in the 

 colors generally, but differ from it in this respect, that, while in lineata the 

 feathers of the neck are white with black tips, and those of the breast, belly 

 and flanks are white in the middle and black at the tips, in segethi the feathers 

 of the neck and breast are uniformly slatey black, and those of the abdomen 

 and flanks are entirely white ; moreover, in segethi the outermost of the supe- 

 rior tail coverts are wholly white, while in lineata they have black shaft 

 lines." 



This species, however, requires very careful comparison with the succeed- 

 ing, before its claims to specific distinction can be fully substantiated. I do 

 not hesitate to express my decided opinion, that they will be found to be 

 identical; for, so far as I can judge of the colors from the descriptions, they 

 are quite similar, and certain descrepancies in the measurements of the two 

 may result from the difference between the French and English inch. The 

 habitat of the two birds is precisely the same ; still, in view of some points, 

 in the descriptions which do not entirely accord, and especially because it 



* These authors themselves remark (p. 284) " on account of the long legs, and the much abbre- 

 viated hallux, our bird should be referred to Bonaparte's new genus Oceanites; but ; t appears 

 that a generic separation can hardly be mad with propriety upon such inconsiderable differences." 

 May 1 be allowed to ask, with propriety, if Fhnpe of bill, peculiar proportions o' tarsus and toes, 

 length of wings and tail, and above all, the fusion of the tarsal plates can be accounted as "in- 

 coneidejrahle differences 1" 



[March, 



