184 ESCHRICHT ON THE 



normal size of this scarcely twelve feet long skeleton (the fresh specimen was 13' long), would 

 be twenty-four feet at least, and that it ought, therefore, not to be reckoned as belonging to the 

 smaller, but, on the contrary, to the larger species. 



The correctness of this opinion is also confirmed by several other less essential circumstances. 

 It is the only female Orca skeleton in the museum having fifty-four vertebrae like Nilsson's and 

 Benzon's specimens, and at one side, at least, twelve ribs. Finally, the phalanges appear in the 

 largest numbers : one, six, four, three, two, as will be seen in the woodcut. 



Another evidence that this only thirteen feet long Orca belongs to the same species as the 

 twenty-one and one third feet long specimen of Mr. Benzon may, perheps, be found in the 

 vomer appearing rather extensively on the palate of both these individuals between the five 

 hindmost teeth, a character not generally met with in the killers. 



But if these conclusions are correct, if this little killer is really to be considered as a very 

 young female of the larger species, then we come to the very important result, that at least the 

 young females have also here a comparatively much lower dorsal fin than the older males. Ac- 

 cording to Mr. Thomsen's measurements and drawing, the dorsal fin of the 13' long female was 

 1' 6" high, or in the proportion of 18 : 156 (0-115 of the length) ; but in both the full-grown 

 males, one of which (Nilsson's) was 22^', the other (Benzon's) 21^', it was four feet, or 0-178 — 

 0-187 of the length of the body. Nevertheless, it seems in the females also to be comparatively 

 higher in the larger species than in the smaller one ; for, whereas its proportion to the length of 

 the body in the Thomsen specimen was still 0-123, it was only as 20^" to 210" = 0098 in the 

 17^' long Greenland specimen, just described. But, at all events, it must be considered as very 

 uncertain whether the Norwegian fishermen by the name of Lille-Vang only understand males 

 and females of the smaller species, or also use the same appellation for the females of the larger 

 species. 



The smallest of the Orca skeletons in the museum under my care is that belonging to one of 

 the animals stranded in 1855 in the Faroe Islands. It might readily be inferred that this skeleton 

 could not belong to the smaller species of Orca, as the crania and the other parts of the skeletons 

 belonging to the animals stranded at the same time proved to be those of large, some even of 

 very large animals ; several of the vertebrae, for instance, were about twice as large in all dimen- 

 sions as the corresponding ones in this skeleton ; but this was also evident from the condition of 

 the skeleton itself, especially as its teeth appeared to be in a still less developed state than those 

 of the Thomsen specimen. 



Nevertheless, a more minute examination of this skeleton must soon lead to the admission 

 that it could not belong to the same larger species as the other little skeleton, that one, namely, 

 of which the Nilsson and the Benzon specimens have been considered as types. It had not 

 fifty-four, but only fifty-three vertebrae ; not twelve, but only eleven pair of ribs. The vomer was 

 not visible in the palate, and though the hands were so much dried up, that the number of the 

 phalanges could hardly be ascertained, yet there seemed to be one or two less in most of the 

 fingers. And what will probably be thought to be still more essential, in almost all its parts the 

 measurements gave very different results. 



