370 ON THE PETRELS COLLECTED DURING 



The same year witnessed the publication of M. Alphonse Milne- 

 Edwards's great work on fossil birds *. Pages 301-341 of the first volume 

 are devoted to the consideration of the osteology of the living Longipennes, 

 composed of the Gulls (Laridae) and Petrels (Procellariidse). The Petrels 

 are considered to be, as regards their osteological characters, allied most 

 closely to the Gulls, with some resemblances to the Steganopodes. " Par 

 quelques-uns de leurs caracteres, les Procellarides se lient aux Totipalmes. 

 Ainsi on ne peut se refuser a reconnaitre une grande ressemblance entre 

 la constitution de la cbarpeute osseuse des -Fregates, des Phaetons, c'est- 

 a-dire des Totipalmes grand voiliers, et celle des Petrels ou des Puffins. 

 Cette analogic a d'ailleurs ete parfaitement saisie par L'Herininier, qui 

 cependant n'avait etudie que la conformation de 1'appareil sternal " (loc. 

 eit. pp. 302, 303). 



A complete skeleton of Prion vittatus is figured on plate 1. fig. 1, with 

 numerous details of the bones of Puffinus cinereus skull (pi. xlix. fig. 12), 

 leg-bones (pi. li.), pelvis and humerus (pi. lii.), sternum and scapular arch 

 (pi. liii.). 



Hydrornis natator (pp. 362-365, pi. Ivii. figs. 18-22), from the Miocene 

 deposits of Langy, is perhaps allied to the Shearwaters (Puffinus), but 

 the remains found (a tarso-metatarsus, and a femur of doubtful owner- 

 ship) do not suffice to decide the point certainly. 



Professor Huxley t places the Petrels with the Gulls, Divers, and Auks 



Zool. Chnll. in the group Cecomorphae of his Schizognathous series. Eespecting their 



Exp. vol. iv. p a i a t e we rea( j Th e Procellariidae differ from the families which have 



just been enumerated (Gulls, Divers, Grebes, Auks, and Penguins) in the 



great expansion of the maxillo-palatines, which become thick and spongy, 



and so closely approach the middle line that, in the Albatrosses, only a 



very narrow cleft is left on each side of the vomer. The front part of the 



vomer itself is much more strongly bent downwards than in the Gulls ; 



and the ascending process of the palatine bone is greatly produced, and 



becomes anchylosed with the vomer. Procellaria gigas [i. e. Ossifraga] 



holds a sort of intermediate place between the Gulls and the Albatrosses, 



the maxillo-palatines being less swollen, and the clefts between them and 



the vomer far larger than in Diomedea. In this species again the basi- 



pterygoid processes are present, though I have not been able to observe 



them in other Procellariidse " (loc. cit. pp. 430, 431). [As regards this 



last sentence, as will be seen below, such basipterygoid processes are the 



rule and not the exception in this group.] In illustration of these 



remarks, views of the palate of " Procellaria " yiyantea and Diomedea 



exulam are given. 



* Recherches anatomiques et paleontologiques pour servir a 1'histoire des oiseaux 

 fossiles de la France (Paris, 1867-1868). 



t " On the Classification of Birds," Proc. Zool. Soc. 1867, pp. 415-472. 



