630 FORM OF THE TOES OF BIRDS. 



the appearance of a large round knob or rather pad. It is not, however, 

 my intention at present to describe the structure of this part in the land 

 birds, I may however remark, that in them, as well as in the others, the 

 examination of the parts in question will materially aid in limiting the 

 number of merely nominal species, by disclosing an identity of form, as 

 well as in separating species that have been confounded, by shewing a di- 

 versity, as I have had occasion to observe, in several species of both kinds. 

 In the aquatic tribes numerous remarkable modifications are observed. 

 Beginning with those which have the extremity of the toe largest and 

 most rounded, we find that the Geese, Ducks, and Gulls, supply good ex- 

 amples. Thus in Lartis marinus, the protuberance beneath the claw is 

 rounded, and covered with small rounded and flattened papillae, of which 

 there is a semicircular terminal series of a larger size, as is represented 

 by fig. 1. 



Fig. 1. Fig. 2. Fig. 3. 



The Pelicans and Gannets are similar in this respect to the Gulls, as 

 are the Cormorants, which, however, have the terminal pad projecting 

 and more pointed. In the Guillemots, also, it is rounded, with small dis- 

 tinct rounded scales. In the Frigate Bird, in which the webs are short, 

 and do not modify the pads, the terminal scales are similar to those of 

 the Gulls. In the genus Lestris, they are smaller, and obscured by the 

 webs, their papillse smaller and more pointed. In the Terns, they are 

 similar to those of the Gulls, but narrower, and with the papillse large. 

 In Phaeton athereus, the webs appear to obliterate the terminal papiHse, 

 which are very small. In all these, the extremities of the toes are more 

 or less rounded, and terminated just beneath the claw by a semicircular 

 series of scales larger than those immediately behind. 



In the AuJcs, however, there is a large scale or plate, on the inner 

 side of the middle toe, and then a series of narrow scales. In Mormon 



