60 Zoology of Colorado 



namensis of Gmelin). The former is pearl-gray above (mottled 

 when young), and the top of the head is black in summer. The 

 latter is silvery-gray above from the nape, and in summer has the 

 head and nape and under parts black; in winter the black of head 

 and under parts is replaced by white, but the hind part of the 

 crown is dusky gray. The tail is short, not long and forked as 

 in Sterna. 



STEGANOPODES 



Distinguished from all the others by hind and front toes 

 connected by a web. Including the cormorants and pelicans. 

 Two species of cormorant occur as stragglers, but the White 

 Pelican (Pelecanus erythrorhynchos) is more frequently seen, and 

 is said to have occasionally bred in former years. The Brown 

 Pelican is represented by a single record, the specimen being pre- 

 served in the State Museum in Denver. 



ANSERES (ANSERI FORMES) 



Cutting edge of bill more or less fringed or toothed ; toes fully 

 webbed ; newly hatched young entirely covered with down. Family 

 Anatidae, with the subfamilies Merginae (Mergansers), Anatinae 

 (ducks with hind toe not lobed), Fuligulinae (ducks with hind toe 

 lobed, known from the mergansers by the flattened and depressed 

 bill), Anserinae (geese) and Cygninae (swans). A noble assemblage 

 of birds, especially abundant during migration. The American 

 Merganser or Sheldrake (Mergus americanus of Cassin) and the 

 Red-breasted Merganser (Mergus serrator of Linnaeus) have red 

 or orange legs; but the Hooded Merganser (Lophodytes cucullatus) 

 has a black bill and dusky legs. Lophodytes is readily known by 

 the high semicircular crest, making the head, seen from the side, 

 appear enormous; but this is more developed in the male than in 

 the female. The species of Mergus have a crest on the posterior 

 part of the head in both sexes, but it is short in M. americanus. 

 In the male, M. serrator has the crest with a patch of reddish- 

 brown streaked with dusky, while in M. americanus it is creamy 

 white or pale salmon. The females with white breast, are not so 

 easily separated, but serrator is smaller, with more slender bill, 

 and nostril near the base of the bill. These birds are all found 



