Boat-bills 147 



withdrawn from the water, and its voice, therefore, was materially modified by 

 this fact." 



As a matter of fact, there is nothing peculiar in the vocal apparatus of the 

 Bittern, and he depends entirely upon it for the production of the notes. It is 

 simply that the natural shyness of the bird makes close observation difficult. In 

 this particular, Torrey on one occasion enjoyed exceptional facilities and gives the 

 following account: "First the bird opens his bill quickly and shuts it with a 

 click; then he does the same thing again with a louder click; and after from 

 three to five such snappings of the beak he gives forth the familiar trisyllabic 

 notes, repeated from three to eight times. With the preliminary motions of 

 the bill the breast is seen to be distending; the dilatation increases until the 

 pumping is well under way and, so far as we could make out, does not subside in 

 the least until the pumping is quite over. It seemed to both of us that the bird 

 was swallowing air, gulping it down, and with it distending his crop; and 

 he appeared not to be able to produce the resonant pumping notes until this was 

 accomplished. It should be remarked, however, that the gulps themselves, 

 after the first one or two at least, give rise to familiar sounds of much the same 

 sort. The entire performance, but especially the pumping itself, is attended 

 with violent convulsive movements, the head and neck being thrown upwards 

 and then forwards, like the Night Heron's when it emits its quow, only with 

 much greater violence. The snap of the bill, in particular, is emphasized by a 

 vigorous jerk of the head." Other observers have witnessed much the same 

 state of affairs and all agree that it is produced only by an apparently violent 

 effort, Brewster stating that a bird he once observed appeared "as if he were 

 afflicted with violent nausea or were trying to get rid of some obstruction in his 

 throat." 



THE BOAT-BILLS 



(Family Cochleariidce) 



The present family comprises but a single genus (Cochlearius] and two 

 species, the oldest known being the South American Boat-bill (C. cochlearius], 

 which ranges from southern Brazil over Amazonia and Guiana to Colombia and 

 Ecuador, and the Central American Boat-bill (C. zeledoni}, which occurs in 

 suitable situations from Mexico to Panama. They are small Night Heron-like 

 birds, sixteen and eighteen inches in length respectively, their most-marked 

 character being the possession of an enormous bill which is greatly depressed 

 and excessively dilated laterally, the lateral outlines being much bowed. The bill 

 approximates three inches in length and nearly two inches in width, and suggests 

 at once possible kinship with the African Shoe-bill, and the naked skin between 

 the branches of the lower jaw is dilatable into a pouch or bag. As further char- 

 acters it may be mentioned that the Boat-bills have four pairs of powder-down 

 tracts, which serve to distinguish them from the Ardeida, which possess but two 

 or three pairs of such areas, while they agree with the latter in having the feather- 



