Dr. H. Burmeister on two Species q/" Balgenoptera. 417 



finger is but little shorter than the second, though somewhat 

 longer than the first, and has the same bones as the second, 

 though each one is rather smaller — 4^, 4^, 3j, 3, 2, and 1 5 inch 

 in length. The fourth finger (which ought to contain, ac- 

 cording to analogy, one metacarpal bone and three phalanges, 

 being the shortest of all) has been completely lost from both fins. 



Of the bones at the side of the sexual aperture, corresponding 

 to the bones of the pubis of the pelvis, one has been preserved, 

 very similar to the same bone in B. jphysalus. It is slender 

 and nearly a foot long, compressed and slightly arched, with a 

 projecting and rather sharp angle on the upper margin, 3 inches 

 above the termination. To conclude, the hyoid apparatus is com- 

 posed of the three bones which are well known in all whales, 

 of which the middle one much resembles the same bone 

 figured in the work of Van Beneden and Gervais, pis. x. & xi. 

 fig. 15 ; but the two lateral ones are not externally so bulky as 

 those in the same figure. The central bone has a ti'ansverse 

 length, measured in a straight line, of 26 inches ; and each of 

 the lateral processes is \b\ inches long. 



We have also the hyoidal apparatus of B. intermedia. It is 

 a little larger ; its middle portion measures 31 inches in length ; 

 and each anterior horn is somewhat larger in bulk though 

 shorter, 14^ inches in length. In the middle portion the two 

 angles at which the horns are united are shorter and more 

 divergent ; and the whole shape of the apparatus is slightly 

 different from that of the other species. For the rest, I 

 can affirm that not a single bone of the one skeleton is 

 identical in shape or size with the corresponding bone of the 

 other ; and this proves clearly a specific difference between the 

 two animals. 



Unfortunately I am not acquainted with the sex of my 

 skeleton of B. jpataclionica so as to certify definitely that the 

 indicated differences are not sexual ; but they appear to me of 

 too great importance to admit this supposition. I have also 

 under my notice the whalebone-plates of the two animals ; 

 but those of B. intermedia are too much destroyed for a com- 

 plete description. Those of B. 'pataclionica are composed of 

 350 laminge on each side of the mouth, of which the 136 

 smaller ones at the end are all white, also the underside of 

 the others, with the bristles of the whole ; whereas the beards 

 of the plates of B. intermedia are completely black, and there 

 is no vestige of the whitish colour of the other species. 



It follows from the explanation here given, according to my 

 views, that there are actually three well-defined species different 

 from the Balccnoptera of our coast of the Atlantic Ocean, which 

 are distinguished in the following manner : — 



