736 PODICEPS DOMINICUS, ST. DOMIXGO GREBE. 



PODICEPS (TACHYBAPTES) DOMmiCUS, Linn. 



St. Doiniiigo Grebe. 



Colymius dominicus, Lixx., Svet. Nat. i, 1766, 223 (C. flttviatilis dominicensis, Briss., vi, 

 64, pi. 5, f. 2).— Gm., Syst. Nat. i, 1788, 593. 



Podiaps dominicus. Lath., Iml. Oru. ii, 1790, 7H5. — Spix, Av. Bras. pi. 101. — Bd., Mex. 

 B. Surv. ii, 1859, pt. ii. Birds, 28 ; B. N. Aui. 1860, pi. 99, f. 1 (uo text, aiul not 

 iu eel. of 1858).— SCL., P. Z. S. 1857. 207.— Law«., Auu. Lye. N. Y. vii, 1861, 334 

 (Panama).— SCL. & Salv., Exot. Orn. i, 1869, 190.— Rkinh., Vid. Med. 1870, 

 17 (Brazil). 



Podicrps (Siilheoctjchts) dominicus, Gray, Hand-list, iii, 1871, 94, No. 10768. 



Si/lbcocyclus dominicus (Br. ?) Coi;es, Pr. Pbila. Acad. 1862, 232. 



Tnchybaptcs dominicus, Coues. 



Hal). — Warmer parts of America. West Indies. North to tbo Kio Grande. Califor- 

 nia (Gitmhel). 



Adult, — Form as above described under bead of the subgenus. Crown and occiput 

 deep glossy steel-blue. Sides of bead and neck all around dark asby-gray, darkest 

 behind, wbere tinged with bluisb. Chin varied with asby and ■white. Upper jiarts 

 brownish-black, with glossy-greenish reflections. Primaries cbocolate-brown, the 

 greater portion of the inner vanes of all, and nearly all of the inner four or five, to- 

 gether with all the secondaries, pure while. Under parts silky-white, thickly mottled 

 with dusky. Upper mandible dusky, the lower mostly yellowish. 



Dimensions. — Length, about 9.50 ; wing, 3.60; bill along culmen, 0.70 ; along gape, 1 ; 

 tarsus, 1.25 ; middle toe, 1.75. 



This small Grebe, the ouly North American* representative of the group, has only 

 lately been ascertained to reach our southern border. It requii'es comparison with no 

 other of our country, its small size alone being diagnostic. Without a series of speci- 

 imens I cannot present the changes of plumage. 



Genus PODILYMBUS, Less. 



< Cohjmlus, LixN., Syst. Nat. i, 1766, 223 (not type). 



< Podiaps, Lath., Ind. Orn. ii, 1790 (not type). 

 =:Podil!pnius, Lkss., Tr. Oru. i, 1831, 595 (P. cnrolinensis, Lath.). 

 =:z Sjilhcocyclus, Bp., Saggio, 1834 (same type intended). 



= Hydrola, Nutt., Man. ii, 1834, 259 (type carolincnsis). 



Char. Bill shorter than head, stoutest in the family, compressed, with obtuse and 

 hooked tip; culmen about straight to the nostrils, tlience declina to-convex ; gouya 

 regularly convex witbout decided angle ; commissure slightly sinnate at base, then 

 straight, then much deflected. Upper mandible covered with soft skin to the nostrils, 

 between which are two ibssa^, the anterior shallow, oblong, the other deep, triangular, 

 separated from the bare loral space by an intervening ridge. Nostrils broadly oval, 

 far anterior. No crests or mils, but shafts of frontal feathers prolonged into bristles. 

 Eyelids peculiarly thickened. Outer three or four primaries abruptly sinuate near the 

 end. Tarsus much abbreviated, comparatively stout, about three-fourths as long as 

 middle toe and claw. Middle and outer toes nearly equal. Basal semipalmation of 

 toes more extensive than in Podiceps. Lobe of hind toe moderate. 



The essential characters of this genus lie in the stout hooked bill, broad anterior 

 nostrils, absence of crest or ruti', bristly Ibrehead, great emarginatiou of primaries, and 

 extensive semipalmation of the toes. The genus Dasijplilus of Swaiuson (Classif. B. 

 ii, 1837, 369), which has been referred here, agrees very well as to the characters .is- 

 signed, but P. polioccphaJus is given as type. In an.y event the name is a synonym, 

 being anticipated iu publication. Hijdroka is based upon carolincnsis, but is antedated. 

 Sylbeocyclns, Bp., was meant for this genus, but, it seems, was by a blunder giveu over 

 head of P. minor. 



There is apparently but a single good species of this genus, although several are 

 indicated by authors. The P. aniarcf'cns of Lesson (with which P. brevirostris, Gray, 

 Gen. of B. iii, 1849, pi. 172, is synonymous), from South America, is a recognizable race 

 which may be defined as follows : 



PoDii^YMBUs PODICEPS var. antarcticus (Less.) Coues. 



Nos. 15663, 15664, Mus. Smiths. Inst., Chili, U. S. Astron. Exped. : Size, coloration, 

 and general .appearance of P. podictps. Bill not shorter than in tins species, but stouter 



* P. minor is given by Nuttall as inhabiting this couutry, but the evidence is alto- 

 gether unsatisfactory. 



