216 Transact ioiis. — Zoology. 



with the extremities and the webs perfectly Hack. The present bird differs 

 further in having the breast and abdomen almost entirely ashy-gi'ey, but this 

 colour is passing off, and therefore seems to indicate a comparatively younj; 

 bird in a transitional state of plumage. The inner surface of the wings is 

 pure white, but there is a broad band of slaty-black extending from the 

 elbow to the carpal flexure where it spreads, and is then continued along the 

 outer edge. 



■f- Frocellaria affinis. Sp. nov. 

 Diag. — Supra saturate cinereus; dorsi plumis et supra-caudalibus nigro 

 terminatis ; alarum minimis et ala spuria nigricanti-brunneis ; primariis extus 

 nigricanti-brunneis, intus albis ; secundariis pallide cinereis, albo anguste 

 marginatis, basaliter albis ; rectricibus saturate cinereis, duabus externis intus 

 albidisj fronte alba cinerascenti-nigro varia ; regione suboculari conspicue 

 cinerascenti-nigra ; facie laterali guttureque albis j pectore imo et abdomine 

 cinereis plumis basaliter albis ; corpore reliquo subtus alba, pectoris lateribus 

 cinereo lavatis, hypochondriis et subcaudalibus inferioribus cinereo variis et 

 minute transfasciatis ; subalaribus albis, exterioribus conspicue nigricantibus : 

 rostro nigro : pedibus sordide flavis, digito externo et membranis interdigitalis 



nigris. 



Hah. — New Zealand. 



Comparative Statement of Measurements. 





P. cooTcii. 



P. 



affinis. 



Extreme length 



12-5 



inches 



13 



inches 



Wing from flexure 



9-25 





10-5 





Tail 



4 





4 





Culmen (following curvature) 



14 





1-25 





Lower mandible (from the gape) 



1-5 





1-5 





Bare tibia ... 



•5 









Tarsus 



1-2 





1-2 





Middle toe and claw ... 



1-5 





1-75 





In rrocellaria leucoptera and P. mollis again we find very similar jjlumage ; 

 but the former (according to Gould) has the wing 2 inches shorter, although 

 the other proportions are the same; while Procellaria mollis, on the other 

 hand, with a decidedly shorter wing than P. affinis, has the tail nearly an inch 

 longer. It has, moreover, a larger tarsus. 



The four species are closely related to one another, and form together a 

 very natural group or sub-gonus. 



