592 Messrs. G, M. Mathews and T. Iredale on some 



is the genus Neonectris with unicolorous, short-tailed forms, 

 one weak-billed and the other strong-billed, and the genns 

 Hemij)vffiniis, a heavy-billed bird, whose bill is abnormally 

 unlike any other speeies in the supergenus. 



The coloration of juveniles does not help us in this group 

 as the downy young passes into the colour-feathering of the 

 adult. Geographical distribution cannot be utilised at 

 present, as we do not know where the birds breed with 

 sufficient exactness to theorise at all. 



Genus Calonectris, nov. 



We propose this genus-name for Puffinus leucomelas 

 Temminck, which differs in coloration from every other 

 member of the group. In its large size it comes near the 

 genus Ardenna, and was placed under this genus by 

 Mathews in his List of the Birds of Australia. Though 

 agreeing fairly well in bill-characters with Ardenna, it 

 differs in the structure of the legs and feet. Ardenna 

 agrees, in having the tarsus very much compressed, 

 ■with Pvjffinus sensu lat. Calonectris has the tarsus com- 

 paratively little compressed, and this feature is only 

 shared with it by the species luhli^ which we temporarily 

 associate with it. When it is recalled that of the twenty- 

 live species included under the genus Puffinus in the 

 ' Monograph of Petrels/ ranging from very large to quite 

 small birds, twenty-three show the great lateral compres- 

 sion and only these two do not, it must be conceded that 

 this is quite a valuable character. In the adult the bill 

 differs obviously from that of Puffinus in the position and 

 structure of the nasal tubes, and at once suggests Procel- 

 laria. The relationship of that genus is, however, with 

 Ardenna through Priofinus, so that the bill formation 

 becomes secondary to the feet formation. 



In this connection the danger of genus lumping as 

 regai'ds anatomical study should be noted. Anatomists are 

 notoriously careless of the nomenclature of the material they 

 handle, and if any of the species of Puffinus (sensu latissimo) 

 were handed to an anatomist for study, it would sooner or 



