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PHYSALUS ASTTABCTICTTS, Gray. The Antarctic Pinner. 

 Synonyms Physalus antarcticus, Gray, S. & "W., p. 164. 



Sibbaldius ? antarcticus, Gray, S. & W., p. 381, Suppl., p. 55. 

 Bol&noptera antarctica, Van Beneden. 



" There has been imported from New Zealand a quantity of finner- 

 fins, or baleen, which are all yellowish-white ; this doubtless indicates a 

 distinct species." (Gray, p. 164.) 



Inhab. Buenos Ayres. 



Genus SIBBALDITJS, Gray. 



Dorsal fin very small, far behind, and placed on a thick prominence ; 

 vertebrae 56-58 ; ribs, fourteen pairs ; nasal bones elongate, narrow, flat, 

 or very slightly hollowed on the sides of the upper surface ; lower jaw 

 with a comparatively slight curve, and a low, obtusely pointed coronoid 

 process ; cervical vertebras free ; head of the first rib bifurcated, articu- 

 lating with the seventh cervical and first dorsal vertebras respectively ; 

 sternum very small, short, broad, somewhat lozenge-shaped. (Princi- 

 pally from Flower.) 



SIBBALDIUS LATICEPS 1 , Gray. Broad-headed Finner. 



Synonyms Balcsna rostrata, Hudolphi. 

 Rorqual du Nord, Cuvier. 

 Pterobalosna boops, Eschricht. 

 Sibbaldius laticeps, Gray, S. & "W., p. 170. 

 Balcsnoptera borealis, ou laticeps, Bened. & Gervais. 

 Hudolphius laticeps, Gray, Suppl., p. 54. 



The colour of this whale is black above and white underneath ; the 

 pectoral fins, according to M. Van Beneden, are entirely black, and not 

 relieved at their base by any white, as in the Pike-whale, B. rostrata. 



The total lengths varied from 31^ to 40 feet, but the animals were 

 young from whom the measurements were taken. The vertebras, ribs, 

 and other bones are small and of delicate structure. 



Inhab. North Sea, Norwegian coasts, Zuyder Zee, &c. 



This small cetacean was usually confounded with its smaller neighbour, 

 the Balsena rostrata of Muller and O. Fabricius, until Dr. Gray, in 1846, 

 detected and clearly pointed out the difference in their anatomy. 



SIBBALDITJS BoEEALis 2 , Lesson. The Flat-back, or the Ostend "Whale. 



Synonyms Baleine d'ostend, Van Breda. 



The Ostend Whale, Guide to Exhib. Char. Cross. 



Balcsnoptera gigas, Esch. & Eeinh., 1857. 



Pterobalcena gigas, Van Beneden, 1861. 



Sibbaldius borealis, Gray, 1866, S. & "W., p. 175. Suppl., p. 



55. 

 Flowerius gigas, Lilljeborg, 1867. 



1 Lotus, broad, ceps, from caput, the head. 



2 Borealis, northern. 



