18S6.] MR. 11. COLLETT ON BAL^NOPTERA BOREALIS. 255 



ill colour. They form on the inner edges of the baleen-plates a 

 dense, rather curly covering, which appears to indicate that the food 

 of this species consists of only very small animals. 



VIII. Blowholes and Furrows. 



The Blowholes lie in two long furrows somewhat converging 

 anteriorlv ; their distance from the end of the snout, in a specimen 

 having a total length of 43 feet, was somewhat over 6| feet (2100 

 millim.). The length of the furrows was from 370 to 410 millim., 

 between these ran a shorter central furrow. 



The Furrows. — These run, as in the other species, along the whole 

 length of the lower jaw, from the symphysis to the angle of the 

 mouth, and extend to the middle of the belly. The upper 8 to 10 

 are short and terminate iu the axilla, and are about 2 feet in length. 

 The others, about 20 in number (from 15 to 34) on each side, are 

 long and extend backwards to the centre of the belly about one foot 

 beyond the end of the flippers. One or more short furrows wedge 

 themselves in between the long ones. 



The total number of long furrows is thus from 30 to 44, to which 

 must be added the 8-10 shorter upper ones ; altogether 38 to 58. 



In addition, the eye is surrounded by two very short horizontal 

 furrows, and in some examples there were also found (as in No. 4) 

 traces of from 20 to 30 short, oblique furrows anteriorto the dorsal fin. 

 The furrows permit the body to expand to nearly double its normal 

 girth. 



IX. Hairy Coverinc/. , 



This consisted in an adult female of 11 hairs on each side of the 

 lower jaw, each about 10 millim. long, and two other hairs on each 

 side, situated somewhat behind these ; altogether 2G hairs. 



In the foetus the covering of hair was more plentiful. On the 

 smallest of the foetuses described further on (No. 1), the total length 

 of which was 1^ metres, the hairs were visible, but quite short. 

 In foetus No. 3, the total length of which was not quite 2| metres, 

 they were arranged on the lower jaw in three rows, comprising 3 hairs 

 in the upper and lower rows respectively and 1 1 in the central row ; 

 altogether on each side 17 hairs. 



On the upper jaw there were only 7 hairs situated in a single row, 

 the two first rather further from each other than the rest. Alto- 

 gether this specimen was provided with 34 hairs on the lower and 

 14 hairs on the upper jaw. 



X. Parasites. 



Parasites of three different sorts have been up to the present 

 time found living upon or in B. borealis ; one of these (not yet 

 examined nor preserved) is a true ecto-parasite, one {Balcenophilus 

 unisetits) is an epizoon, and two Echinorhynchi are ento-parasites. 



I could find no trace of ecto-parasites on the specimens examined 



