ON BELMULLET WHALING STATION. 123 



at t lie tip than that of B. musculus, but in both cases the exact shape 

 varies somewhat. 



The tail fin could not be examined in the adults for the reasons stated 

 above, but in the foetal specimens mentioned below the concavity of the 

 tail fin was particularly noticeable. The surface of the tail is concave 

 beneath, and in the foetus the flukes themselves are bent downwards 

 so as to bring the tips towards each other. 



III. Colour Descriptions, &c. 



As most, if not all, the whales must have been dead several hours 

 (from six to twelve) before being examined, great care had to be 

 exercised in noting actual colours. It is well known that all the colours 

 darken after death. In the case of contrasting light and dark (in 

 patches, Ac.) the relations would probably not be very much altered for 

 some time, so that variations in the arrangement of patches of colour 

 were noted. In the case of B. musculus variations in colour-details 

 were found to be very common. The asymmetrical jaw-coloration is, 

 however, quite definite and constant and the dark patches on the under 

 side are often confined to the furrows of the breast folds. 



Specimens of the skin were taken (a) from tail where the second 

 layer of black integument is very thick; (b) from the body so as to 

 include some of the peculiar white spots ; (c) from breast folds of 

 B. sibbaldii to include a portion of a bright yellow patch ; (d) from 

 breast folds to include portion of pink coloration (? blcod or pigment). 



IV. Hairs. 



The distribution of these on both B. musculus and B. sibbaldii was 

 found to be substantially the same as described by I). G. Lillie (Proc. 

 Zool. Soc, 1910). They occur (i) along top of head, (ii) along the side 

 of lower jaw, and (iii) as vertical rows at tip of lower jaw. The actual 

 numbers in any one of these positions appear to vary somewhat. 



A similar distribution was also found in the foetal specimens of 

 B. musculus and B. sibbaldii examined. 



The hairs appear to be rather more numerous on tip of mandible in 

 the case of B. sibbaldii than in B. musculus. 



Specimens of hairs with underlying tissues were taken for further 

 examination. 



V. Jacobson's Organ. 



In the case of B. musculus the two grooves under the tip of snout 

 which represent the openings of this organ generally have short canals 

 leading out of the hinder ends of the grooves. These canals are from 

 \ to 1 inch in length when they exist, but in some cases there are 

 no canals at all. Such canals, so far as I have seen, are absent in 

 B. sibbaldii. 



These ducts appeared to be in much the same state in the foetus 

 examined. In the case of a fcetus 8 feet long of B. sibbaldii, a short 

 duct was present on the right side, but no duct could be detected on the 

 left side. 



