36 E. LÖNNBERG, UUNTK1BUTIONS TU THE EAUNA UE SOUTH UEUKCilA. 



On a young specimen (8,i 5 m.) Sörling counted 24 furrows on the ventra] 

 surface of the breast. They begin at the chin and extending backwards they diverge 

 somewhat on the breast, bnt converge again and become partly confluent on the 

 middle of the belly in front of the navel (Pl. VI fig. 28). The longest furrows seem 

 to end on a level with the hind-end of the navel, the lateral ones are shorter. 



A similar number I have counted on a foetus (conf. Pl. IX). In the northern 

 race the number of furrows, according to True {20), varies between 14 and 22 on 

 the American side of the ocean, and, according to Särs, between 20 and 30 on the 

 European side. As the furrows do not run regularly but one furrow may sometimes 

 be seen to divide into two and two to unite into one the counting is somewhat 

 difficult and may lead to different results, if done according to different principles. 

 The results to which different authors have come, cannot therefore be directly com- 

 pared when it is not stated at which place the counting is done. The counting of 

 the furrows of the southern Humpback, as quoted here, has been done just between 

 the pectorals. 



Concerning the number and situation of the dermal tubercles of the South 

 Atlantic Megaptera Sörling has not made any notes, but two photos taken by him 

 and reproduced here (Pl. VI fig. 25 & 26) throw some light on this. On the snout 

 there are evidently as well lateral as median tubercles. The former are placed in an 

 irregular row and are perhaps 8 — 9 in number. The median ones are distributed 

 from the tip of the snout to the sides of the blow-hole. These tubercles of the 

 upper jaw are not so well developed in a foetus (Pl. IX) measuring l-,. 4 s m. in length. 

 They may, however, easily be discerned, and their arrangement is shown on Pl. IX. 

 They are evidently not quite regularly placed, but there may, nevertheless, be recog- 

 nized some series and groups. Eleven tubercles of varying size form an irregularly 

 wavy series along the lateral portion of the upper jaw. Five are found in a median 

 row from the snout to below the boss in front of the blow-holes. A single tubercle 

 is seen laterally from the same boss, and two more sit further back and higher up 

 at the sides of the blow-hole. 



It is of great interest to note that there sits a hair on top of each of these 

 tubercles described, and sunk into them so that in some instances, where the hair 

 itself has fallen out, the rather wide pore in which it had rested, remains. 



The situation and arrangement of these hairs make it evident that they are 

 the homologues of vibrissse. In the adult the hairs seem to have disappeared as 

 Sörling did not observe any on either jaw. This might pro ve to be a difference 

 from the Humpback of the Northern Atlantic, which is said to be provided with 

 such hairs even when adult. 



With regard to the maxillary tubercles and their arrangement the northern 

 and the southern form eorrespond fairly Avell, although True, (20) and other authors 

 quoted by him, mean that they could distinguish two lateral rows in addition to the 

 median one, which is hardly possible in the southern atlantic Humpback in spite 

 of that the number of tubercles (although varying) is about the same. The tubercles 

 of the lower jaw of the southern atlantic Humpback form a cluster on either side 



