

50 MR. J. W. CLARK ON THE NARWHAL. [Jan. 17, 



there exist species of Flounders of which single individuals, contrary 

 to the general rule, have their eyes on the left side of the head in- 

 stead of on the right, or vice versa. If any thing similar could occur 

 in the Narwhal ; if the cranium might be twisted to the right in- 

 stead of to the left, then the tusk also woidd most likely be twisted 

 in the same uncommon direction." By such a theory as this, he 

 urges, Scoresby's remarkable instance of a female Narwhal tusk, with 

 a dextrorsal spiral, may be explained. 



There are now at least eleven bidental skulls in existence in dif- 

 ferent European museums, including the one at Cambridge. I have 

 collected all the information I could about them, partly from per- 

 sonal observation, partly from the kindness of friends, and partly 

 from books and figures. 



1. Hamburg. — The celebrated specimen brought home in 1684 

 by Dietrich Petersen, Captain of the ' Golden Lion.' Female. It 

 was originally deposited in the Museum of Herr Rdding, a private 

 collector of curiosities, but is now in the town museum, where I 

 saw it in 1866. Unfortunately I had no opportunity of measuring 

 it. The following dimensions are from Anderson* : — left tusk 7' 5" 

 long, 9'' in girth ; right 7 long, and 8" in girth. Figured originally 

 by Anderson, whose engraver has made the right side the left, and 

 vice versa. His figure has been copied, with its errors, by Lacepedet, 

 and very badly, but corrected, by Klein J. 



2. Copenhagen. — In the Zoological Museum of the University 

 there is a complete adult skeleton with two fully developed tusks ; a 

 skull in a similar condition ; and a skull with two very large tusks, 

 but unfortunately much damaged. In the Museum of the Veterinary 

 School is a fourth skull §. 



3. Christiania. — Avery fine skull, sent from Copenhagen. I took 

 the following measurements in 1866 : — 



Total length, from extremity of occipital condyles 



to end of longest tusk 101" 



Length of exserted portion of longest tusk 6' 5" 



Girth 8" 



The other tusk is now 6^" shorter, but has been broken. Apparently 

 they were originally of the same length. It is 7" in girth at the same 

 point as the other. The tusks diverge 2" at their origin, 8" from 

 the end of the broken tusk to the opposite point of the entire one. 



4. Amsterdam. — The skull figured by Vrolik ||. He gives no 

 history of it ; but Reinhardt believes it to be one that was sold in 

 1846 by the Directors of the Copenhagen Museum. It will be re- 

 marked that the right tusk is the longest. Vrolik believes it to be of 

 a female, but, as Reinhardt considers, on no very sufficient grounds. 



* Nachrichten von Grunland. 

 t Histoire des Cetaces, pi. 9. 



| Hist. Piscium, Arid, ad Missus ii. iii. iv. plate iii. 



§ These facts, which I noted in 18C>(i, have been confirmed, and more accurately 

 stated, in a letter kindlv sent me by Prof. Eeinhardt at the beginning of this year. 

 || Vrolik, I. c. 



