STRANDED ON THE BRITISH COASTS. 157 



sends up a lateral extension backwards on each side, behind the 

 region of the dorsal fin. 



(9) Blackfish or Pilot- Whale {Glohicephcda mehxna Traill). 



Three records in the five years: Hampshire, 1913; Northum- 

 berland, 1914; and Cork, 1915; all in March; besides a school 

 of about 50 individuals which were stranded at Penzance on 

 July 1, 1911. 



The Pilot- Whale reaches a length of at least 26 ft. and is 

 usually, completely black. It possesses about 10 large teeth, 

 about yV in- in basal diameter, on each side, in the front half of 

 each jaw. The "forehead" is enormously swollen, and the 

 pectoral limbs are very long and narrow, reaching a length of 

 about 4 ft. 6 in. It is well known to associate in large schools, 

 which are hunted in the Orkneys, the Faroe Islands, and 

 elsewhere. As many as 2000-3000 individuals have been driven 

 ashore at one time on the coast of Norway (Hjort, 1902, p. 119) ; 

 and a record of 1000 specimens observed at the Lofoten Islands, 

 on Sept. 4, 1890, has been given by Grieg (1897, p. 8). 



(10) Risso's Grampus {Grampus griseiis Cuv.). 



Four records : Jersey, Aug , 1913 ; S. Devon, Aug., 1917 ; and 

 S. Devon, Nov., 1913 ; the last record consisting of two 

 individuals, presumably mother and calf, althougli the sexes 

 were not definitely ascertained. It will be observed that all 

 these records belong to the S. W. extremity of the British Islands ; 

 and there is little doubt that this is a more Southei'U species 

 which only just reaches our seas. 



Bisso's Grampus is recognizable by its blunt head, without 

 beak; and by the considerable i-eduction of the number of 

 its teeth. Of these, none are present in the upper jaw, wiiile the 

 lower jaw possesses 4 or 5, of considerable size, with a basal 

 diameter of as much as | in., at the front extremity. Adult 

 individuals reach a length of about 12 ft. Flower's Memoir 

 (1874) may be consulted for information regarding tliis species. 



(11) Bottle-nosed Dolphin [Tursiops truncatus Mont.). 



Ten records: one in February (Scilly Islands, 1915), one in 

 May (Merioneth, 1916), and the remainder during the period 

 June- August. With the exception of one individual (Essex, 

 1914), the determination of which was not quite certain, all were 

 from the Southern coast of England, or from the Welsh or 

 Lancashire coast. 



The Bottle-nosed Dolphin reaches a length of al)oiit 12 ft., 

 and possesses about 25 teeth on each side of each jaw. As in 

 some other Dolphins, about two of these, at the front end of the 

 series, are very. small and usually remain concealed beneath the 

 gum ; while the I'emainder are relatively lai'ge, with a basal 



