CETACEA. 75 



Cervical vertebrae : first free, second and third united by spi- 

 nous process, not by the body, thin ; rest free, thin. 



Monodon, Artedi, Gen. 78 ; Synon. 108 ; Hill. Anim. 313. t. ; 



Linn. S. N. ed. 6, 17; Schreb. ; Gray, ZooL E. $ T. 29, not 



Swainson. 



Narwal, Schonev. Ichlh. 28. 



Narvalus, Lacep. Get. 163; DumeriL; Rafin. Anal. Nat. 61,1815. 

 Ceratodon, Brisson, R. A. i. 231, 1762; Illiger, Prod. 142, 1811 



Wagler, N. S. Ampli. 34, 1830. 

 Diodon (or Diodonta), Storr. Prod. Mam. 42, 1780. 

 Monoceros, Charlet. Exerc. Pise. 47. 



Monoceros piscis, Willoughb. Pise. 42. t. A. f. 2, App. p. 12. 

 Oryx, Oken, Lehrb. Naturg. 672, 1815. 



Right tusk generally not developed. Female generally with- 

 out tusk, but sometimes has one : see Linn. Trans, xiii. 620. 



In the Museum of the College of Surgeons there are several 

 Hunterian preparations of the skull of this animal, Nos. 1147, 

 1148, 1149, 1150, 1151, showing the two rudimentary teeth in- 

 closed in the cavity, in the female, and the single exserted one in 

 the male skulls. 



Mr. Knox observes, the female Narwal skulls have two rudi- 

 mentary teeth in the upper jaw, which are rarely protruded. In 

 the foetus, on each side the upper jaw, in the usual place, are 

 two hollow teeth, obviously the extremities of the spiral per- 

 manent teeth of the male ; they are completely imbedded in the 

 jaw ; and if the animal is a male the left tooth continues to grow, 

 the right after a time fills up, its central cavity containing the 

 pulp disappears, and after attaining a growth of five or six 

 inches, the jaw elongates to correspond with the growth of the 

 animal and the other tooth, and the abortive tooth remains im- 

 bedded in the jaw for life. Trans. R. Soc. Edin. ii. 413. 



The Monodon spurius, O. Fab., the type of the genus Anar- 

 nacus of Lacepede (Cetac. 164), appears by later research to have 

 been founded on an inaccurate description of an Hyperoodon, the 

 lower jaw having been mistaken for the upper, and the converse. 



1. MONODON MONOCEROS. The NARWHAL. 

 Black ; when old, whitish-marbled. 



Monodon monoceros, Linn. Faun. Suec. 2. 16; Syst. Nat. i. 105 ; 



Schreb. Sangth. t. 330 ; Desm. Mam. 523; Fischer, Syn. 516 ; 



Scoresby, Arct. Reg. i. 486, iii. t. 12. f. 1, 2; Fleming, Mem. 



Wern. Soc. i. 146, fig. ; Gray, ZooL E. $ T. 29 ; Sow. Brit. 



Misc. t. 

 M. unicornu, Linn. Mus. Adolph. i. 52. 



D2 



