BLACK-THROATED LOON. 295 



in the middle, direct at the base and toward the end, the ti]> 

 narrow and pointed ; the lower mandible Avith the intercrural 

 space very long and extremely narrow, the lower outline of 

 the crura straight, the dorsal line ascending and very slightly 

 convex, the edges sharp and involute, the tip attenuated. 



The mouth is of moderate width, but extensile, the gape- 

 line commencing under the eyes. Nostrils small, sub-basal, 

 linear, direct ; eyes of moderate size ; apertures of ears very 

 small. The feet are short, and placed at the extremity of the 

 body ; the tibia covered by the skin of the body almost to the 

 end, the tarsus short, extremely compressed, edged before and 

 behind, covered all over with angular scales. The hind toe 

 extremely small, elevated, connected with the second by a 

 membrane, which is partly free, forming a lobe narrowing to 

 the end ; the anterior toes long, the outer longest ; the inner 

 with a two-lobed membrane ; the interdigital membranes nar- 

 row, and emarginate ; all the toes with numerous scutella. 

 The claws are small, depressed, convex above, obtuse. 



The plumage is short, dense, and firm ; on the head and 

 neck very short, soft, and blended ; the feathers of the upper 

 parts oblong, glossy, those of the fore part of the back, and 

 the scapulars, truncate ; of the lower parts short, blended, but 

 stiifish, and considerably glossed ; those on the lower parts of 

 the sides of the neck much incurved, with the terminal fila- 

 ments stiff. The wings are of moderate length, narrow, and 

 convex ; the primaries strong, tapering, the first longest, the 

 second scarcely shorter, the rest rapidly decreasing ; the 

 secondaries very short, broadly rounded. The tail is ex- 

 tremely short, rounded, of eighteen rather firm, rounded 

 feathers. 



The bill is black ; the feet greyish-blue externally, pale 

 flesh-coloured internally ; the webs flesh-coloured ; the claws 

 dusky, yellowish at the base. The upper part of the head 

 and the hind neck are of a hoary bluish-grey, the fore part 

 and sides of the head darker ; the throat and fore part of the 

 neck are purplish-black, that colour extending about six 

 inches, and ending in an angle. On the upper part of this 

 dark band is a transverse narrow interrupted band of linear 

 white streaks. The sides of the neck are blackish-brown. 



