1871-3 MR. J. W. CLARK ON THE NARWHAL. 51 



5. Weimar. — In Froriep's Museum. The left tusk is fully deve- 

 loped, the right projects only a few inches beyond the skull. Figured 

 by Albers*. Its authenticity has been questioned by Dr. Jager ; and 

 undoubtedly the fact of the right tooth being so small renders it very 

 necessary to examine the skull most carefully. 



6. Hull. — In the Museum of the Philosophical Society. Procured 

 in 1838 from a whaler. It is of a young animal, the left tusk 

 measuring 20", the right $", exclusive of the portion within the 

 skull f. 



7. Paris. — A young skeleton recently sent from Copenhagen, 

 where it had been preserved for some years in the Museum stores. 

 The longest tusk projects 2\\ the shorter one only a few inches. 



Besides these, three others have been mentioned. 



1. A skull sent down from Greenland in salt, and exhibited at 

 Amsterdam in the 17th century. This fact rests on the authority 

 of Zorgdragerj, who says the longest tusk measured &, the shorter, 

 which was broken, 1'. 



2. Leuckart§ saw a bidental skull at Vienna in 1841. The tusk 

 on the right side was two-thirds shorter than that on the left. The 

 spiral was sinistrorsal. This skull was certainly not there when I 

 examined the collection in 1868. Possibly it was destroyed in the 

 fire of 1848, which did great damage to the Museum. 



3. Sowerby || mentions that a Narwhal came ashore at Friestone, 

 in Boston Deeps, Feb. 15, 1800. He remarks, "it perfectly agreed 

 with the name given by Linnaeus, in having but one tooth, looking 

 like a horn ; but on examining the upper jaw, it was very evident 

 that the other tooth had been lost ; and we have since seen a perfect 

 skeleton of the head of this animal with the two teeth fixed in their 

 proper sockets." Unfortunately he gives no further particulars ; so 

 that one cannot judge whether his opinion was justified by the ap- 

 pearance of the skull, or rests merely on his own notions of symme- 

 trical propriety. 



It has been argued, by Rapp in the first instance, and by others 

 since, that these bidental skulls are all forgeries. It might doubtless 

 be possible to hollow out the right side of the skull in such a way 

 as to admit of the insertion of a smaller tooth ; and consequently 

 those skulls where one tusk is much smaller than the other ought 



* Icones ad Anatomen comparatam illustrandam. It has been shown by both 

 Vrolik and Jager that Albers was wrong in eiting nine other cases of bidental 

 skulls. One only of his is truly bidental, No. 5, the Hamburg specimen. Nos. 1, 

 2, 6, and 7 are probably other figures of it ; No. 3 is the Stuttgart specimen de- 

 scribed by Eeisei ; No. 4 is that at Copenhagen, described by Tychonius ; Nos. 

 8 and 9 are those figured by Sir E. Home. His error arose from regarding the 

 undeveloped tooth on the right side as something abnormal, and as a genuine 

 second tusk. 



t These particulars have been most obligingly communicated to me by Mr. 

 R. Harrison, Curator of the Museum. 



I Zorgdrager, p. 33. 



§ F. S. Beuckart, ' Zoologisehe Bruchstiicke,' Stuttgart, 1841, p. 48. I owe 

 this reference to Vrolik, p. 22, /. c. 



|| Brit, Miscellany, Bond. 180fi, p. 17, tab. ix. 



