130 5/r E. Home on tJie Tusks of the Narwhale. 



of a skull with two tusks of equal lengths, is that given by 

 Dick Peterson. 



These facts make it necessary to take from this species of 

 whale the name given to it by LiNNiEus, of Monodon Mono- 

 ceros, since they prove that it is a very improper one. 



The greatest length which has been given to the left tusk, 

 before the right has cut the gum, is fifteen feet : this account 

 is mentioned by Egede in his Natural History of Greenland, 

 1741. 



The lower jaw, both in the male and female, has a rounded 

 edge, in which there is no part from which teeth can grow. 



explanation of the plate. 

 (See Plate VII.) 



Fig. 1. The young skull of a male narwhale, shewing the 

 permanent tusk in its socket, the milk tusk ready to be pro- 

 truded. 



Fig. 2. The female skull, with the two milk tusks ready to 

 be protruded, having acquired their full size, and canals being 

 formed through which the points are to pass out. 



Fig. 3. A section of a milk tusk to shew that it is solid. 



Fig. 4. The lower jaw, in which there is no place for 

 teeth. 



Fig. 5. A section of a full grown tusk, to shew the cavity 

 in the middle, and that the parts at the point and at the root 

 are solid. 



From tbe Press of 



W. BULMER^ Co. 



Cleveland-row, St. James's, 



London, 



