CHAPTER IV. 



THE COMMON FINBACK, BAL.ENOPTERA PHYSALUS (Linn.). 



This species is the " Common Finback " of European waters. Hundreds 

 of individuals have been taken at the Finmark whaling stations since 1874, and 

 scores have been I'ecorded as stranding at various points on the coasts of p]ur(>pe 

 during the 18th and 19th centuries. The species has been, on tliis account, 

 more carefully studied than any other Finback. Sars's diagnosis of the species, 

 published in 1878 (75, 17), is as follows: 



" Length of full grown individuals reaching to 70 feet. 



"Body slender; the greatest height scarcely exceeding J- the leno-th ; behind 

 the navel very much attenuated, the posterior half very narrow and maiutaininc 

 almost the same depth throughout. 



" Color above and on the left side of the lower jaw dark gray, below white ; 

 color of the back descending obliquely behind the pectoral fins so as to leave only 

 a narrow median longitudinal area (below) along the posterior part of the body. 



" Mouth equalling al>out \ the length of the body; upper jaw seen from above 

 very nari'ow, wedge shaped, gradually decreasing in width toward the apex. 



" Pectoral fins small, scarcely exceeding \ the length of the bod}^, narrowly 

 lanceolate, with the posterior angle often but little distinct ; the external surface 

 showing: the coloi- of the back, the internal surface and the whole anterior margin, 

 white. 



"Dorsal fin quite high, ti'iangular, with the scarcely curved apex directed 

 obliquely backward ; situated behind a vertical line drawn through the anal orifice. 



" Caudal fin uniformly white below, with the margins dusky. 



" Whalebone dull bluish, varied with lighter color; some near the apex [of the 

 upper jaw] white." 



The admirable figure accompanying Sars's article ({ilate 2) agrees exactly with 

 the diagnosis. It represents the right side of the whale, showing the lowei- jaw 

 and the anterior whalebone white, a character of importance, as will appear later. 

 Sars's diagnosis in Norwegian is somewhat fuller than that in Latin, which is 

 translated above, and may be profitably included here : 



" Length of full-grown individuals reaches to 70 feet. 



" Body of especfally slender and attenuated foi'm, with the greatest height 

 never exceeding \ the total length, back of the navel suddenly and strongly di- 

 minishing, so that the whole of the posterior portion of the body becomes unusually 

 small and almost eveiywhere of one height as far as the root of the flukes. 



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