BLACK-THROATED DIVER. 517 



The length of the Loon is about 2 feet 8 or 10 inches. The head, 

 neck, and tail coverts glossed with deep purplish-green, on a black 

 ground. A short transverse bar on the throat, a collar on the middle 

 of the neck, interrupted above and below, and the shoulders, white, 

 broadly striped on the shafts of the feathers with black. Whole 

 upper plumage, wings, sides of the breast, flanks, and under tail 

 coverts, black ; all, except the quills and tail, marked with a pair of 

 white spots near the tip of each feather : these spots form rows, and 

 are large and quadrangular on the scapulars and interscapulars, 

 round and smaller elsewhere, least on the rump. Under plumage 

 and inner wing coverts white ; the axillaries striped down their 

 middles with black. Bill and legs black. Irides brown, (often 

 blood red.) 



In the young of the year, the head, occiput, and all the inferior 

 parts of the neck are ashy -brown ; small ashy and white points 

 upon the cheeks. Throat, fore part of the neck and the other lower 

 parts pure white. Feathers of the back, wings, rump, and flanks, 

 dark brown in the middle, bordered and edged with bluish-ash. 

 Upper mandible of the bill ash-grey, the lower whitish. Iris pur- 

 plish-red. Feet dark brown externally, interiorly, as well as their 

 membranes whitish. It is then Colymbu^ immer, Gmel. i. p. 5C8. 

 sp. 6. 



BLACK-THROATED DIVER. 



(Colymbus arcticus, Linn. Lath. Ind. ii. p. 800. sp. 4. Bonap. 

 Synops. No. 369. Temm. ii, p, 913, Rich, and Swains. North. 

 Zool, ii. p. 475. Black-throated Diver, Penn. Arct. Zool. ii. p. 

 No. 444. The Speckled Diver, or Loon, Edwards, pi. 146. [adult 

 from Hudson's Bay,] Le grand Plongeon, Buff, Pi, Enlum. 914. 

 [young]. Naum. vog, Nachtr. t. 30, f. 60. [adult male].) 



Sp. Charact. — The bill from the rictus about 3^ inches long; the 

 upper mandible slightly curved ; lower not wider in the middle 

 than at base, and without groove beneath; tail of 18 feathers. — 

 Adult black, slightly marked with white, the back unspotted ; be- 

 neath white ; head greyish-brown ; the neck beneath glossy black, 

 with a stripe on each side of it marked with white. Young ashy- 

 brown ; beneath white ; a blackish band often on the sides of the 

 neck. 



44 



