THE VOYAGE OF THE ' CHALLENGER.' 373 



agree with the Steganopodes and Erodii, differing from the " cyclocoelic " 

 Pelargi, Eaptatores, and Laridse. 



1881. In a posthumous paper*, published in the "In Memoriam" 

 volume of his works, the late Professor A. H. Garrod describes the 

 anatomy of the Diving Petrel (Ptlecanoides urinatrix), based upon an 

 examination of specimens collected during the ' Challenger's ' voyage. 

 Pelecandides has no ambiens muscle, in which respect it differs from all 

 the other true Petrels, and resembles Bulweria alone of them in its 

 formula A.X. The main vein of the leg, the femoral vein, is superficial 

 to, instead of deep of, the tendon of the femoro-caudal muscle, a 

 peculiarity hitherto only observed in the genus Dacelo amongst the 

 Kingfishers. "The Procellariidaa may be divided into the Storm-Petrels 

 or Thalassidrominae, and the true Petrels or (Estrelatinae, the former 

 differing from the latter in possessing the accessory Bemi-tendinosus 

 muscle." These two groups therefore correspond to those already 

 distinguished by Garrod in his former paper as the "Storm-Petrels" 

 and the Fulmaridse. 



As regards the systematic position of the Petrels it is said" I may 

 mention that since writing my paper ' On Certain Muscles of Birds, and 

 their value in classification,' I have changed my views as to the affinities 

 of the Procellariidae. In that communication I place the family amongst 

 the Anseriformes ; now it is evident to me that it is with the Ciconii- 

 forrnes that they are most intimately related. E/eason for my change of 

 opinion will be found in what here follows." Unfortunately the paper 

 was never completed, and the reasons mentioned not stated in 

 consequence. 



In a paper read before the Zoological Society on June 18th of the 

 same yearf I proposed to make the so-called Procellaria nereis of Gould, 

 the Procellaria fregata of Professor Garrod's earlier papers, the type of 

 a genus to be called Garrodia, it being not a true Petrel at all, but one of 

 the allied group without caeca and with a formula AB.XT, the Thalassi- 

 drominaB of Garrod, which includes besides the genera Oceanites, Fregetfa, 

 and Pelayodroma, the family so formed constituting my Oceanitidse. 



1882. Lastly, in the concluding part of the Atlas to the great work 



on Madagascar J, MM. Grandidier and A. Milne-Edwards have given Zool. Chall. 

 figures of the skeletons and separate bones of Priori vittatus, Puffinus Exp. vol. iv. 

 chlororhynclius, and Thalassidroma oceanica. 



* 85. " Notes on the Anatomy of Pelecanoides (Puffinurid) urinatrix" loc. cit. 

 pp. 521, 522. 



t Proc. Zool. Soc. 1881, pp. 735, 736. 



\ Histoire physique, naturelle et politique de Madagascar, publie'e par Alfred 

 Grandidier, xv, ; Histoire naturelle des oiseaux, x. iv., Atlas iii. (Paris, 1881), plates 

 293, 294, 297, 298, 299, 300. 



