440 COLYMBIDZ.—PODICIPEDIDZ. 
subtus pure albo, loris et facie laterali albidis nigro striolatis; gutturis et pectoris plumis obsolete 
brunneo marginatis; corporis lateralibus plumis medialiter brunneis, griseo vel albo late marginatis; 
subalaribus et axillaribus pure albis, his apicem versus brunneis; crissi plumis et subcaudalibus brunneo 
terminatis: rostro nigro, apice pallidiore; pedibus livide grisescenti-ceruleis, intus pallide carneo tinctis, 
palmis brunnescenti-nigris intus pallidioribus; iride coccinea. Long. tota circa 20-5, ale 14:2, caudee 
2°6, culm. 2:95, tarsi 3°8. (Descr. spec. adulti hiemalis ex Vancouver I. Mus. Brit.) 
Hab. NortTHern Parts oF BoTH HEMISPHERES, ranging in winter to Lower California, 
- the Gulf of Mexico, and the Mediterranean Sea 34 °,—Mexico, Valley of Mexico 
(Herrera? 8). 
_C. glacialis breeds from the Northern United States northward. In winter it is 
said to visit the Gulf of Mexico and Lower California. Herrera has recorded the 
species from the Valley of Mexico’ ’, but we have not as yet seen a specimen from 
Central America. | 
In its winter-haunts this Diver frequents the coasts and the open sea, and is not 
easily approached. Its great powers of diving and swimming are well known. 
Fam. PODICIPEDIDA. 
The Grebes differ from the Divers in having the hallux raised above the level of 
the fore toes; all the toes have scalloped webs or lateral lobes, united at the base. 
The tail is rudimentary. Culmen short or only moderately long, somewhat curved 
downwards towards the tip, straight, or occasionally slightly upturned; feathers on 
forehead normal; secondaries equal to, or not much shorter than, the primary quills; 
metatarsus considerably shorter than the middle toe and claw (cf. Grant, Cat. Birds 
Brit. Mus. xxvi. p. 502). 
Three genera of Podicipedide are recognized by Mr. Grant (J. c.), all of which occur 
in Central America. The family is cosmopolitan in its range. 
Grebes usually make their nests of decaying rushes and water-plants. The eggs are 
cavered with a chalky-white substance, underneath which the bluish-green colour of 
the shell is seen; they are generally concealed by rushes cast over them by the 
parent birds on leaving the nest. 
ZECHMOPHORUS. | 
Aichmophorus, Coues, Proc. Acad. Philad. 1862, p. 229; Grant, Cat. Birds Brit. Mus. xxvi. 
p. 549 (1898). 
In this genus the secondary quills are short, the longest being nearly equal to the 
ninth or tenth primary, and the metatarsus to the middle toe and claw, or a little 
shorter than the latter, the culmen being very long and pointed. 
‘Two species are known, ZZ. major and 4H. occidentalis. The former is an inhabitant 
of South, the latter of North-western America, occurring in Central America in 
winter. 
