RED-THROATED DIVER. 565 
ture seems almost certain. On the Ohio river I have seen them in great 
numbers when they seemed to take pleasure in accompanying steam- 
boats, swimming along side, and often diving under. When diving their 
movements are more like those of a turtle than those of a bird, the legs 
moving in the horizontal plane of the body, and the wings assisting 
with short flaps, executed by moving the proximal joints only. 
CoLYMBUS ARCTICUS Linnzeus. 
Black-throated Diver. 
Back and under-parts much as in the last species; upper part of head and hind neck, 
bluish-ash or hoary-gray ; fore neck purplish-black. The young resemble those of that 
species but will be known by their inferior size. Length, under 2} feet; extent, about 
3; wing, 13 or less; tarsus, 3; bill, about 24. 
Habitat, Northern Hemisphere. 
Very rare or accidental visitor, now first given as_a bird of Ohio. Mr. 
H. H. Chubb writes: ‘I mounted one specimen for a gentleman in 
Garrettsville last fall [1880]. It was shotin Sandusky Bay. This isthe 
only specimen I have seen.” 
CoLYMBUS SEPTENTRIONALIS Linneeus. 
Red-throated Diver, 
Colymbus septentrionalis, WHEATON, Ohio Agric. Rep. for 1860, 371, 379; Reprint, 1861, 
13, 21; Food of Birds, ete., Ohio Agric. Rep. for 1874, 575; Reprint, 1875, 15.— 
. LANGpon, Cat. Birds of Cin., 1877, 18; Revised List, Journ. Cin. Soc. Nat. Hist., i, 
1879, 187; Reprint, 21. 
Colymbus septentrionalis, LINNEZUS, Syst. Nat., i, 1766, 220. 
Blackish ; below white, dark along the sides and on the vent and crissum; most of 
head and fore neck bluish-gray, the throat with a large chestnut patch; hind neck 
sharply streaked with white on a blackish ground, bill black. Young have not these 
marks on the head and neck, but a profussion of small, sharp, circular or oval white 
spots on the back. Size of the last, or rather less. 
Habitat, Northern Hemisphere. 
Spring and fall migrant ; not rare on Lake Erie, especially in the fall, 
rare in other portions of the State. Mr. Langdon mentions two or three 
individuals taken in the vicinity of Cincinnati. I have never met with 
it. 
FAMILY PODICIPIDA., GREBES, ETC. 
Feet four-toed, lobate. Hallux lobate, free. Tail rudimentary. Head with a naked 
loral strip and bristly or variously lengthened feathers. Bill straight or decurved at 
end, compressed, acute. 
