Bii-ds of Celebes: Podicipedidae. 91 5 



yellow head, D. exulans, when adult, by its large size (wing 670 — 740 mm), 

 white plumage with black remiges, and whitish legs and feet. The young of 

 the two latter are dusky (the face of D. exulans white) and require more care- 

 ful discrimination from D. nigripes (cf. Water B. N. Amer. 1884, II, 346; Cat. B. 

 1896, XXV, 11. cc). 



ORDER PYGOPODES. 



This order should apjiarently be restricted to contain the Grebes and the 

 Divers, as the Alcae, though very like in general appearance, are shown by 

 Fiirbringer and Gadow to deviate in many important points of structure in 

 which the two groups might have been expected to agree. 



The Pyffopodes are natatorial birds, taking their food by diving, and are 

 best characterized by their legs, which are situated so far back as to necessitate 

 an almost upright carriage on land, where the bird rests upon the back of the 

 tarsus as well as on the foot; by the very reduced tail which is hardly notice- 

 able; by the small wings, rounded to fit the body; and by the straight, pointed 

 bill, not serrated along the edges. The feet are either webbed (Coh/mbidae) 

 or lobed (Podicipedidae), the outer toe is as long or more often longer than the 

 middle one, the hallux, when present, is small, lobated, and not united with the 

 other toes. The eggs are unspotted, and the young are able to swim immediately 

 after being hatched. 



FAMILY PODICIPEDIDAE. 



GENUS PODICEPS Lath. 



The toes of the Grebes are four in number, lobated, i. e. furnished with broad 

 side-flaps, the hallux small and situated on the inner side of the tarsus at a 

 higher level than the anterior toes; the tarsus is much compressed and furnished 

 with rugose scutellae along its hind edge upon which the bird rests; there is 

 hardly any appreciable tail, what there is of it consisting of hair-like feathers; 

 the wing is small, fitting the body, 1 2 primaries. The nest is a floating mass 

 of decaying vegetation; the eggs are white, but soon become discoloured from 

 the nest-materials, with which the bird also has the habit of concealing them 

 on leaving the nest. The Grebes are almost cosmopolitan in range. 



^392. PODICEPS TRICOLOR (G.R.Gray.). 



Moluccan Little Grebe. 



a. Podiceps fSylbeocyelusj tricolor (1) Gray, P. Z. S. I860, 366. 



Podiceps tricolor (1) Wall., P. Z. S. 1863, 36, 487; (2) Salvad., Orn. Pap. 1882, m, 

 470; (3) W. Bias., J. f. 0. 1883, 140; (4) Pleske, Bull. Ac. Petersb. 1884, XII, 



115* 



