PODICIPID^ — THE GREBES — ^CHMOPHORUS. 421 



A.. Bill slender, the length oi' tlie culnien from 2i to G times greater than the basal depth. 



a. Size large (wing, 6.45-9.00 inches ; culmen, 1.50-3.05). 



1. 2Bchinophorus. Neck extremely long (almost equal to the body in length); bill longer 



than the head, very slender and acute (the culmen 5 to (3 times longer than the depth 

 through the base), straight, or even slightly recurved ; tarsus equal to the middle toe and 

 claw ; no colored tufts, ruffs, or patches about the head, and plumage the same at all 

 stages and seasons. 



2. Colymbus. Neck much shorter than the body ; l>ill about equal to the head, stout (cul- 



men about 3j times the basal depth), the tip obtuse, and the outlines more or less curved ; 

 tarsus shorter than the middle toe with claw ; adult in the breeding-season ornamented 

 by colored ruffs, tufts, or patches about the head, the winter plumage and the young very 

 different. 



b. Size small (wing, about 5.00-6.00 inches ; culmen, .9.5-1.10). 



3. Dytes. Neck much shorter than the body ; bill much shorter than the head, the culmen 



equal to about 3 to 3i times the basal depth ; tarsus about equal to the middle toe 

 without the claw ; adult in breeding-plumage with colored tufts or patches about the 

 head ; young and winter adult very different from the breeding-plumage. 



c. Size very small (wing, 3.50-4.00 inches ; culmen, less than 1.00). 



4. Podiceps. Neck much shorter than the body ; bill shorter than the head, the culmen less 



than 3 times the basal depth ; tarsus decidedly shorter than the middle toe without claw ; 

 in the American species, adult in breeding-plumage without ornamental tufts or patches. 

 B. Bill very stout, the length of the culmen less than twice as great as the basal depth. 



5. Podilymbus. Size rather small (wing, about 4.50-5.00 inches) ; Itill much shorter than 



head, the culmen mucli curved terminally ; tarsus shorter than middle toe without claw. 

 No tufts in summer plumage, but bill crossed by a broad black bar, and throat covered 

 by a black patch. 



Genus -SJCHMOPHORUS, Coues. 

 ^chmoplwrus, Coues, Pr. Ac. Nat. Sci. Philad. April, 1862, 229 (type, Podiceps occidcntalis, Lawii.). 



Char. Neck extremely long (almost as long as the body), the bill longer than the head, very 

 slender and acute (the length of the culmen 5 to 6 times greater than the depth through the base), 

 straight, or even slightly recurved ; tarsus equal to the middle toe and claw. Plumage plain plum- 

 beous-dusky or blackish above, pure white beneath, including the whole under side of head and 

 neck ; much the same at all seasons and stages. 



Only one species of this genus is known ; this, however, represented by two supposed races, 

 distinguished mainly, if not entirely, by their dimensions. They differ as follows : — 



1. Occidentalis. Wing, 7.45-8.50 inches (average, 8.07) ; culmen, 2.60-3.05 (2.78). Hah. 



Western North America in general, but chiefly the interior. 



2. Clarki. Wing, 6.70-7.75 inches (average, 7.31) ; culmen, 2.10-2.48 (2.25).i Hah. Pacific 



coast of North America. 



^chmophorus occidentalis. 



THE WESTERN GREBE. 



Podiceps occidentalis, Lawk, in Baird's B. N. Am. 1858, 894. — Baird, Cat. N. Am. B. 1859, no. 



704. —Coop. & Suck. N. H. Wash. Terr. 1860, 281, pi. 38. —Coues, Key, 1872, 336 ; Check 



List, 1873, no. 608. 

 jEclunoi^lwrus occidentalis, Coues, Pr. Ac. Nat. Sci. Philad. 1862, 229 ; 2(1 Check List, 1882, no. 



846. — RiDGW. Nom. N. Am. B. 1881, no. 729. 

 Podiceps {^chmophorus) occidentalis, Coues, Birds N. W. 1874, 727. 



^ The above measurements are from specimens in tlie National Museum collection. That the two 

 foi-ms intergrade, however, not only in measurements, but also other supposed distinctive characters, is, 

 we believe, clearly demonstrated by Mr. Henshaw in 15ull. Nutt. Orn. Club, October, 1881, pp. 214 218. 



