SLENDER-BILLED GUILLEMOT. 251 



Strepsilas, but is much more allied to the latter, with which it agrees 

 in form and proportions, the principal differences being in the tail, which 

 is not rounded, but even, in the want of scutella on the tarsi, and in the 

 form of the bill at its extremity, the upper mandible in place of being 

 a little recurvate and depressed, having its extremity arched and the 

 point a little decurved. Were the latter worn off, it would agree with 

 that of Strepsilas. Conceiving this bird to present characters sufficient 

 to constitute a sub-genus in immediate connection with Strepsilas, I pro- 

 pose to give it the name of Aphriza Townsendi-, the generic appellation 

 (derived from a<ps^oi and ^aw) being expressive of the habit of the bird, 

 as indicated in the notice of its discoverer, who appears to me to have 

 the best claim for the specific name. 



SLENDER-BILLED GUILLEMOT. 



Uria Townsendi. 



^ PLATE CCCC)^XIX. Adult and Young. 



I have received not less than four specimens of this small Guille- 

 mot from Dr TowNSEND, who procured them on the north-west coast 

 of America, not very far from the mouth of the Columbia River. The 

 changes of colour in birds of this genus are well known to be consider- 

 able ; and I have represented two individuals, supposing one to be an 

 adult, and the other a young bird in its first plumage. 



Uria Townsendi. 



\ 

 Adult. Plate CCCGXXIX. Fig. 1. 



Bill shorter than the head, straight, slender, much compressed, acute. 

 Upper mandible with the dorsal line convex and declinate, the ridge 

 very narrow, the sides erect and convex toward the end, the edges sharp 

 and inflected, with a distinct notch near the tip, which is rather acute 

 and caniculate beneath. Nostrils medial, narrow near the margin, 

 in the fore parts of the long nasal sinus, which is feathered. Lower 

 mandible with the angle long and very narrow, the dorsal line ascend- 

 ing and straight, the sides nearly erect, but convex, the edges sharp 

 and inflected, the tip very acute. 



