596 Messrs. G. M. Mathews and T. Iredale on some 



been procured at Christmas Island, but I purpose to deal in 

 detail with this most interesting collection at a later period 

 when I have obtained more material.- In this case we might 

 have : — 



" Puffinus ubscurus obscurus Gmelin. Christmas Island. 

 „ ,, opisthomelas Coues. Revillagigedo 



Group. 

 „ „ newelli Henshaw. Sandwich Island." 



This was written when the first consignment with a 

 solitary specimen of this bird was available. Study of the 

 three specimens in connection with P. opisthomelas Coues 

 and the description of P. newelli Henshaw suggests the 

 absolute rejection of P. obscurus Gmelin until topotypes are 

 available. We further do not feel inclined to consiiler the 

 present form as subspccifically related to the others in view 

 of the difference in general coloration, while the difference in 

 size between P. opisthomelas Coues and P. neivelli Henshaw 

 is too great to treat them in this way, especially as they 

 differ in the somewhat important character of the mottling 

 of the side of the neck, to say nothing of the difference in 

 the colouring of the malar region, under tail-coverts, etc. 



Genus Thyellodroma Stejneger. 



Thyellodroma Stejneger, Proc. U. S. Nat. Mus. vol. xi. 

 1888, p. 93. 



Type (by original designation) : Procellaria pacijica 

 Gmelin. 



The species-name paciflca is almost characteristic of tliis 

 genus, as it would appear to be confined to the Indo-Pacific 

 Oceans and not to range into the Atlantic. Hemipuffinus 

 has also a restricted range, while Reinholdia is only very 

 locally known at present. 



We have placed the species nativitatis under Pvffimis, but 

 it may be that it should be placed in conjunction with this 

 genus ; wherever it is classed it is quite an aberrant form. 

 Probably the wisest course would be to designate it with a 



