TUBINARES 445 



TUBINARES 



Definition. — ITostrils produced into tubes. Aftershaft present, aquiuto- 

 oubital. Oil gland tufted. Skull sohizognathous, holorhinal. 

 Two carotids present. Large supra-orbital glands. 



The peculiar form of the external nares, which has given 

 to the group its name, characterises it. It is a character 

 which is found in no other group,' but in all members of 

 the present. The Tubinares are nearly the only large group 

 of birds which can thus be diagnosed by a single character. 

 The tube itself is, according to Foebes, whose ' Challenger ' 

 memoir upon the group forms the chief classic upon the 

 subject, in Majaqueus, and probably in other genera, 

 caused by a growth of the catilaginous walls of the nasal 

 sacs. The degree of fusion between the two tubes varies in 

 different genera. In Procellaria, for example, they quite 

 coalesce and the external aperture is single. In Pelecanoides 

 there is a distinct and not broad septum ; while in Bulweria 

 and others the septum is so broad that the tubes almost 

 appear double. 



The petrels are web- footed birds with a small hallux, 

 which in Pelecanoides is quite absent. The web does not 

 take in the rudiinentary hallux. The general number of the 

 rectrices is twelve, but Ossifraga has as many as sixteen. 

 The aftershaft is always present. The pterylosis does not 

 vary greatly ; the dorsal and ventral tracts are well separated 

 upon the neck. The ventral pteryla is divided on the 

 neck ; in the pectoral region each branch again divides. 

 The dorsal tract divides at the middle of the scapulae into 

 two, which unite later, thus enclosing a space. 



The tongue varies much in size and in the amount of its 

 spiny bordering or covering. In Dwnedea, for instance, it is 

 much covered superiorly with spines. In (Estrelata and 

 others the tongue has a bordering of spines which are lateral 



' It has been pointed out that the complex and somewhat protuberant 

 nostrils of Chionis bear a little resemblance to those of the Tubinares, but are 

 differently developed. 



