6 CHARACTERS OF THE ORDERS. 



epithelium moderately thick and rugous. Intestine long and 

 rather wide, with moderate cceca ; rectum with a large glo- 

 bular cloacal dilatation. Legs generally very short, and 

 placed far behind ; tarsus extremely compressed ; toes four, 

 with the hind toe small, or three only, generally long, and 

 connected by Avebs ; claws small and obtuse. Wings narrow, 

 pointed, sometimes very small, but varying greatly in size ; 

 tail extremely short, or of moderate length. 



ORDER XIX. MERSATORES. 



Bill of moderate length, generally stout, straight, com- 

 pressed, more or less decurved at the end, opening to beneath 

 the eyes. Tongue fleshy, rather narrow, tapering, pointed, 

 horny beneath at the end. Qjlsophagus very wide through- 

 out, with its walls thin; proventriculus dilated. Stomach 

 small, muscular, wdtli large radiated tendons, and thick, 

 dense, longitudinally rugous epithelium. Intestine rather 

 long, narrow ; coeca very small, cylindrical ; rectum with a 

 large globular cloacal dilatation. Legs of moderate length, 

 or short, rather slender, not much compressed ; toes of mode- 

 rate length, slender, connected by w^ebs, spreading, the first 

 very small, elevated, and free, or wanting; claws small, 

 arcuate, rather obtuse. Wings very long, rather narroAv, 

 much pointed ; tail generally moderate. 



The differences of these three orders, as to habits, as well 

 as structure, are so obvious, that he who, residing on the sea- 

 shore, and taking daily note of some of the species of which 

 they are composed, is not struck by them, must be peculiarly 

 unobservant, or unaccustomed to compare the objects that 

 attract his notice. High in air, advancing on gently-arched 

 and out-spread wings that winnow a passage for them over 

 the far-spread sea, is seen advancing from the north a flock 

 of large birds, that are observed as they draw nearer to be 



