of the Family of Anaiidce. 19 



and seems to be undescribed. Guided by the same views, 

 we next inquire what other ducks present us with the pro- 

 jecting laminae of the Shovellers ; or where we shall look for 

 the gradual diminution of a structure so important to these 

 birds. This diminution we find in the sub-genus, 



CHAULIODUS, 



of the ' Northern Zoology,' founded upon the well-known 

 Gadwall duck, a bird so repeatedly described, that it is sur- 

 prising how any part of its structure should have escaped 

 observation. It is, however, certain that this bird makes as 

 near an approach to the Shovellers as any other yet known. 

 The form of the bill, indeed, is no longer spatulate, or percep- 

 tibly broader towards the end ; but the laminae of the upper 

 mandible are still very fine, distinct, and more numerous than 

 those of any other form subsequently mentioned, for they 

 project a full tenth of an inch beyond the margin. The tail 



now begins to be lengthened, and, in a new species from Africa 

 (C. Capensis), which I have recently received, is so much 

 attenuated, as to evince an evident affinity to the pin-tail duck, 

 forming the sub-genus 



DAFILA, 



of Dr. Leach. Nature has now so far receded from the typical 

 form, that one of the chief peculiarities of that structure is 

 nearly lost, and another considerably modified. The laminee 

 of the upper mandible, which, in the Chauliodus strepera (Sw.), 

 are so much shorter than those of the true shovellers, and are 

 still more abbreviated in C. Capensis, become almost concealed 

 by the margin of the bill in the bird now before us. The most 



C 2 



