358 



DISCOVERY REPORTS 



-T . . 



U 13 16 17 18 



LENGTH OF WHALE IN METRES 



Fig. 97. Spacing of baleen plates in Fin whales. The plotted points represent the spacing of the baleen plates 

 in individual whales. (Black symbols represent South African whales and circular ones South Georgia 

 whales.) 



VENTRAL GROOVES 



The description already given of the ventral grooves in Blue whales may be taken as 

 applying also, in almost ever}' particular, to Fin whales. A minor distinction perhaps 

 is to be found in the posterior endings of the grooves. In Blue whales they may end 

 evenly in the neighbourhood of the umbilicus but in many cases may be continued 

 beyond this point in the form of irregular or broken up extra grooves and there may 

 be a median groove joining the umbilicus and genital aperture. In Fin whales, on the 

 other hand, the grooves always end very evenly near the umbilicus, and the median 



Fig. 98. Mammary grooves, genital aperture, etc., in female Fin whales (semi-diagrammatic); to 

 show variations of the extra grooves in this region. ?n, mammary grooves. 



