PSEUDORCA CRASSIDENS. 217 



would scarcely be advisable to found even on this figure a detailed comparison with our dolphin. 

 I shall not therefore lay any particular stress on the circumstance, that the Grampus seems to 

 have a much thicker, and a much more swollen head than our dolphin, and that the back-fin, 

 to judge from the dravi^ing, is placed still further backwards than in the latter, although 

 Gray has not hesitated to set down this position of the back-fin as one of the characters of his 

 new genus. But even though it might be less prudent to found a comparison between our 

 dolphin and D. griseus on the other diffferences which it may be possible to derive from 

 D'Orbigny's figure, yet there is at all events one difference, moreover completely confirmed by 

 the description of the same observer, and fortunately appearing in a part of the body which is 

 attacked by putrefaction only very late, and the form and outline of which cannot be greatly 

 altered by this process, I mean the pectoral fins. For these are not only much longer in the 

 Belpldnus griseus than in our species ; but they must even be comparatively longer than the 

 pectoral fins of the ca'ing-whales themselves ■} for in the ten feet long individual, examined by 

 D'Orbigny, they had the very considerable length of three feet, and thus their length was only 

 contained three and one third times in the total length, a proportion between the length of the 

 pectoral fin and that of the animal itself, that never occurs in the ca'ing-whale. The pectoral 

 fin is, moreover (both in the drawing, and according to the measurements given), placed un- 

 commonly far backwards in D. griseus (three and a half feet behind the point of the snout), so 

 that its point, when the fin is laid along the body, almost reaches as far back as the posterior 

 margin of the dorsal fin. When to this extremely important difference in the length and 

 position of the fin, we add the no less essential one, appearing in the teeth, our dolphin keeping 

 all its teeth until its greatest age, whereas I), griseus, provided even that, generally speaking, it 

 retains its teeth in the upper jaw beyond the first period after its birth, or in other words, 

 provided these teeth really ever become fully developed, loses them at all events so early, that not 

 even a single one of them has remained in any of the individuals hitherto examined, though 

 amongst these have been young animals of a length of only little more than seven feet,^ if finally, 



^ Cuvier's description of the pectoral fins of Delphinus griseus is somewhat obscure, perhaps 

 a consequence of the falling out of a word. However, if the meaning really is (as I should almost 

 suppose), to ascribe to this dolphin pectoral fins comparatively shorter than those of the ca'ing-whale 

 (Cuvier's D. globiceps), it seems to me that it is only a want of attention that has caused Cuvier to 

 express himself in this manner ; for in this case the measurements which he has given (the length of 

 the animal ten feet, that of, the pectoral fin three feet), would contradict his description, which is to 

 the following effect : " Leur pectorales pointues soat longues de trois pieds sur un pied de largeur å 

 leur base, moins qu'au globiceps, mais plus qu'å la figure de dauphin ventru de Hunter," (' Rech. s. 1. 

 Oss. Foss.,' 2me ed., t. v, 1, p. 284; 4me ed., t. viii, 3, p. 99). 



^ It is very well known, that it is not only in his Delphinus griseus, that Cuvier mentions such a 

 falling out of the teeth of the upper jaw. According to him, the same is found to take place in a 

 more advanced age also in other great, blunt-headed dolphins, among others in the ca'ing-whale. 

 "Without being willing, or venturing, to deny the correctness of the statement generally, yet, as far as 

 the last-mentioned dolphin is concerned, I cannot but suppose, that such a falling out of the teeth 

 must at any rate be of very rare occurrence. I have seen no trace of it in any of the numerous 

 ca'ing-whales' crania (some of very old animals), which the Royal Museum, during a long course of 

 years, have frequently received from the Faroe Islands, and once from Greenland ; nor have I seen 

 any cranium wanting the teeth of the upper jaw, among the many crania preserved in other collections 

 in this town, except as far as they might have been lost during, or after, the preparation, nor have I 



28 



