(50 THE VOYAGE OF H.M.S. CHALLENGER. 



least so. All agree in having a deeply four-notched sternum, in having well developed 

 uncinate bones, in the possession of one or two accessory wing-ossicles developed in the 

 termination of the tensor patagii tendons, in the spiny tongue (? Adamastor), and the 

 palatal armature of spines (? Adcimastor), and in there never being even indications of 

 lateral lamellaj on the beak. 



CEstrelata differs from its allies in having only a single ulnar ossicle, there being two 

 in all the others. 



Puffinus ami Adamastor are more closely connected together than they are with 

 Majaqueus, easily distinguishable by its more normal nostrils, less compressed tarsi, and 

 specialised (? Adamastor) syrinx. Bulweria is a peculiar form, with no very close ally, 

 and must be regarded as a highly specialised form, as shown in its myological formula 

 being reduced to A.X, and its peculiar cuneate tail. It has no close relationship at all 

 to the Stormy-Petrels, as already pointed out by Dr. Coues, 1 and Garrod. 2 



These views on the classification of the Tubinares may be represented in the annexed 

 diagram (p. Gl). 



V. THE AFFINITIES OF THE TUBINARES. 



The Tubinares as a group may be shortly defined as follows : — 



Holorhinal schizognathous birds with a large, broad, depressed, pointed vomer, and 

 truncated mandible ; with the anterior toes fully webbed, and the hallux either very small 

 and reduced to one phalanx, or absent ; with a tufted oil gland and large supra-orbital glands 

 furrowing the skull ; with the external nostrils produced into tubes, usually more or less 

 united together dorsally ; with an enormous glandular proventriculus and small gizzard 

 of unusual shape and position, and with the commencing duodenum ascending ; with a 

 completely double great pectoral muscle, and a well-developed pectoralis tertius ; with 

 the femoro-caudal and semi-tendinoms muscles always present, and the ambiens and 

 accessory femoro-caudal only exceptionally absent. 



Some, at least of these characters — the structure of the hallux, the formation of the 

 nostrils 3 and the form of the stomach are cpfite peculiar to the Tubinares, not being 

 found in any other birds, though of universal presence in these. These features alone 

 would at once suffice to distinguish them from any other Avian order, whilst the combin- 

 ation of other characters is as unique. It is therefore a difficult task to assign to this 

 group a satisfactory position in any arrangement of the class Aves, owing to its much 

 isolated position. 



S.C., 18C6, p. 13!). - Coll. Papers, p. 221. 



3 The Caprimulgine genus Siphonorhis (Sclater, Proc. Zool. Soc, 1861, p. 78) perhaps approaches the Tubinares 



more nearly in this point than any other hint known to me. 



