60 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 (? Adamastor), and in there never being even indications of 
lateral lamellee on the beak. 
(Estrelata differs from its allies in having only a single ulnar ossicle, there being two 
in all the others. 
Puffinus and 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,! and Garrod.” 
These views on the classification of the Tubinares may be represented in the annexed 
diagram (p. 61). 
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-tendinosus 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? and the form of the stomach are quite 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 
eroup a satisfactory position in any arrangement of the class Aves, owing to its much 
isolated position. 
S.c., 1866, p. 139. 2 Coll. Papers, p. 221. 
8 The Caprimulgine genus Siphonorhis (Sclater, Proc. Zool. Soc., 1861, p. 78) perhaps approaches the Tubinares 
more nearly in this point than any other bird known to me. 
