NATATORES. 429 



with great velocity ; with their heads erect, and their fin-like 

 wings hanging down as half arms, they " look like so many chil- 

 dren with white aprons on." Hence they are said to " unite in 

 themselves the qualities of men, fowls, and fishes ! Like men, 

 they are upright ; like fowls, they are feathered ; and like fish, 

 they have fin-like instruments that beat the water before them 

 and serve for all the purposes of swimming rather than flying." 

 They are covered more warmly with feathers than any other 

 bird, so that the sea seems entirely their element. 



FOURTH FAMILY. PETRELS or FULMARS. 

 Procellarida, (Lat. from procella, a storm.) 



The form of the beak in the birds of this family is very re- 

 markable ; it appears to be constituted of several separate pieces 

 soldered together. The .upper mandible has the basal part sep- 

 arated from the tip by a deep, oblique furrow, and has on its 

 summit a tube, (or two tubes united into one,) containing the nos- 

 trils ; the point of this mandible takes the form of a curved and 

 pointed claw or nail ; the lower mandible is likewise seamed in 

 a similar manner, and its tip is hooked downwards. (Plate IX. 

 fig 10.) 



The front toes are united by a membrane ; the hind toe is re- 

 duced to a mere claw, which is elevated upon the tarsus and 

 sometimes wanting. The wings are usually long, and the flight 

 powerful. 



The Petrels are eminently birds of the ocean, rarely approach- 

 ing the land, except in the breeding period. Some of them ap- 

 pear to be almost always on the wing, following the course of 

 ships for days together without alighting. Their food consists 

 of small mollusks and crustaceans, and the oily particles which 

 float upon the surface of the sea. In high latitudes, some of 

 them feed with much voracity on the fat of slaughtered whales. 

 Hence their flesh becomes apparently saturated with oil ; and 

 when alarmed, many of them occasionally eject fetid oil from 

 their nostrils, as a defence. This family includes a number of 

 species, about eight of which are found in America. 



The COMMON FULMAR, Procellaria glacialis, (Lat. icy,) or 

 Fulmarus glacialis, is considered the type of the true Petrels, 

 having a stout, thick bill, with the upper mandible considerably 

 hooked at the tip, and sulcated or furrowed ; the lower mandi- 

 ble is straight and slightly truncated ; the nostrils are united in 

 a single tube ; the legs of only moderate length. This bird is 

 a, native of the Polar regions, but is found, though in less num- 



