OBJECTIONS TO THE THEORY 313 



to the longer axis of the mouth. They arise from the 

 palate, and are attached by flexible membrane to the sides 

 of the mandible. Those standing toward the middle are 

 the longest, being about one-third of an inch in length, 

 and they project -14 of an inch beneath the edge. At 

 their bases there is a short subsidiary row of obliquely 

 transverse lamellae, in these several respects they resem- 

 ble the plates of baleen in the mouth of a whale. But 

 toward the extremitv of the beak they differ much, as 

 they project inward, instead of straight downward. The 

 entire head of the shoveller, though incomparably less 

 bulky, is about one-eighteenth of the length of the head 

 of a moderately large Balasnoptera rostrata, in which spe- 

 cies the baleen is only nine inches long; so that if we 

 were to make the head of the shoveller as long as that 

 of the Balsenoptera, the lamellae would be six inches in 

 length — that is, two-thirds of the length of the baleen 

 in this species of whale. The lower mandible of the 

 shoveller-duck is furnished with lamellae of equal length 

 with those above, but finer; and in being thus furnished 

 it differs conspicuously from the lower jaw of a whale, 

 which is destitute of baleen. On the other hand, the 

 extremities of these lower lamellae are frayed into fine 

 bristly points, so that they thus curiously 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. 



From 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 



—Science — 14 



