186 



NATURAL HISTORY OF BIRDS. 



Such a species is our North American white pelican (Pelecanus erythrorhynchos), 

 formerly confounded with the species figured. A very distinctive and remarkable 

 feature, however, is the irregular protuberance on the culmen, which is equally devel- 

 oped in both .sexes. Mr. Robert Ridgway, who, in 1868, during a visit to the island 

 in Pyramid Lake, Nevada, discovered the regular shedding of this horn, or ' centre- 



FIG. 90. Pelecanus onocrotalus, European white-pelican. 



board,' as it was appropriately called by the inhabitants of the neighborhood, describes 

 it as follows: "The maxillary excrescence varies greatly both in size and shape. 

 Frequently it consists of a single piece, nearly as high as long, its vertical outlines 

 almost parallel, and the upper outline quite regularly convex, the largest specimen seen 

 being about three inches high by as many in length. More frequently, however, it is 

 very irregular in shape, usually less elevated, and not infrequently with ragged ante- 



