Species of the Genus Tlialassogeron. 505 



figs. 1, 2), which shows the culininicorn perfectly rounded 

 posteriorly_, and not pointed. 



Failing to identify my specimen with the help of the 

 ' Monograph of the Petrels/ I was beginning to think that 

 it belonged to an undescribed species^ but as soon as I 

 compared it with Mr. Verrill's description and figure, 

 I scarcely doubted that the bird examined was a specimen 

 of T. eximms. It agrees with Verrill's description, which 

 runs as follows : — 



*' Forehead and fore part of the head on top pure white 

 from the bill back to about the centre of the eyes^ from 

 there gradually blending into pale ash-grey, which extends 

 around on to the cheeks and sides of the head, but again 

 fades out to pure white on the throat. In front of the eye, 

 almost from the base of the bill, and bordered on top by 

 the pure white of the forehead, is a very dark sooty-grey 

 patch, ivhich extends over the eye and around to the centre of 

 the lower lid, and the space immediately behind the eye being 

 pure white, blending into the ash of the surrounding parts. 

 Back of the head and neck light ash-grey, gradually darken- 

 ing posteriorly. . . . The extreme base of the culmen 

 does not reach to the feathers of the forehead, but is 

 separated by a narrow strip of naked skin and is bordered 

 by a very narrow line of dark brown. From where the 

 brown ceases the culmen is bright yellow, gradually 

 deepening in tint and becoming orange at about two-thirds 

 the distance from the base, and finally dull red at the 

 unguis, the extreme tip of the mandible being horn-colour. 

 All the rest of the bill is pure black, except the extreme 

 outer end of the lower mandible, which is light horn- 

 colour." 



According to Mr. Verrill the lower mandible lacks 

 completely the transverse yellow bar at its base, but I doubt 

 the correctness of the statement, as all the allied species 

 have the yellow bar. Certainly the specimen we have 

 shows a prominent yellow line at the base of the lower 

 mandible. 



