318 MIBGELLANBOm OMEGTtONS TO THE 



resemble the plates of baleen. In the genus Prion, a 

 member of the distinct family of the Petrels, the upper 

 mandible alone is furnished with lamellae, which are well 

 developed and project beneath the margin; so that the 

 beak of this bird resembles in this respect the mouth of a 

 whale. 



Prom the highly developed structure of the shoveller's 

 beak we may proceed (as I have learned from information 

 and specimens sent to me by Mr. Salvin), without any great 

 break, as far as fitness for sifting is concerned, through 

 the beak of the Merganetta armata, and in some respects 

 through that of the Aix sponsa, to the beak of the common 

 duck. In this latter species the lamellse are much coarser 

 than in the shoveller, and are firmly attached to the sides 

 of the mandible; they are only about fifty in number on 

 each side, and do noit project at all beneath the margin. 

 They are square-topped, and are edged with translucent, 

 hardish tissue, as if for crushing" food. The edges of the 

 lower mandible are crossed by numerous fine ridges, which 

 project very little. Although- the beak is thus very inferior 

 as a sifter to that of a shoveller, yet this bird, as every one 

 knows, constantly uses it for this purpose. There are 

 other species, as I hear from Mr. Salvin, in which the 

 lamellae are considerably less developed than in the common 

 duck; but I do not know whether they use their beaks for 

 sifting the water. 



Turning to another group of the same family. In the 

 Egyptian goose (Chenalopex) the beak closely resembles 

 that of the common duck; but the lamellae are not so 

 numerous, nor so distinct from each other, nor do they 

 project so much inward; yet this goose, as I am informed 

 by Mr. E. Bartlett, " uses its bill like a duck by throwing 

 the water out at the corners," Its chief food, however, is 

 grass, which it crops like tire common goose. In this latter 

 bird the lamellae of the upper mandible are much coarser 

 than in the common duck, almost confluent, about twenty- 

 seven in number on each side, and terminating upward in 

 teeth-like knobs. The palate is also covered with hard 

 rounded knobs. The edges of the lower mandible are 

 serrated with teeth much more prominent, coarser and 

 sharper than in the duck. The common goose does not sift 

 the water, but uses its beak exclusively for tearing or cut- 



