\ WHALEBONE WHALES—MACKINTOSH 247 
result from a scarcity of other species, but concludes that in fact its 
occurrence in the catches at South Georgia is representative of its 
actual occurrence in the sea, and that it arrives at a time when the 
sea temperature is at its highest. It is commonly taken off temperate 
and tropical African coasts in winter, where it is probably a little more 
numerous than blue and fin whales. It also figures in the catches 
off the west coast of South America and is known in Australasian 
waters. 
In the North Atlantic as in the south it seems to avoid the coldest 
water, for it does not appear to be recorded from Spitzbergen. It is 
commonly taken from the north of Norway to Spain, and off New- 
foundland and New England. D’Arcy Thompson’s charts of Scottish 
catches (1918, 1919) indicate that whereas blue and fin whales are 
mostly taken outside the 100-fathom line, sei whales are found both 
in the shallow water over the continental shelf and in the deep water 
beyond it. However, Harmer (1927) and Fraser (1934) show that 
there are comparatively few records of sei whales being stranded on 
the British coasts. In the North Pacific it is recorded from Alaska to 
Mexico and Japan. 
In some years exceptionally large catches of sei whales have been 
made in European waters. These may be partly due to scarcity of 
other whales, but they are probably examples of the irregular move- 
ments of this species. 
(8) Balaenoptera brydei 
Bryde’s whale is very similar to the sei whale. Olsen (1918) de- 
scribed certain external differences, not all of which were accepted 
by Andrews (1916). A further publication by Olsen (1926) refers 
to differences in the baleen, flipper, ventral grooves, etc., and Lonn- 
berg (1931) notes some distinctions in the skeleton. It seems prob- 
able that the two species are distinct, but the question should not 
perhaps be regarded as finally settled yet. 
All that can be said of the distribution of this whale is that it is 
frequently listed in the catches of South African stations and rarely 
elsewhere. It has been recorded from the West Indies, Lower Cali- 
fornia, and Norway, but Harmer (1928) considers that its identifica- 
tion, at least at the two latter localities, is open to doubt. 
; (9) Balaenoptera acutorostrata 
Except for the pigmy right whale, the lesser rorqual, or minke, is 
the smallest of the whalebone whales, and seldom exceeds 30 feet in 
length. Apart from its size it is easily distinguished by a whitish 
band across the outer surface of the flipper. 
This is a widely distributed species but scarcely large enough to 
