1910.] AND INVERTEBRATES OF ST. HELENA, 109 



by Cooper in Proc. Oal. Acad. Nat. Sci. 1863, who, however, 

 represents the pectoral as larger than that described by other 

 writers, namely, half the length of the body. Thus the three 

 species are known with certainty to occur together only at 

 St. Helena, Madeira, and Japan ; while albacora has been 

 identified at Samoa. It is possible that all three occur in the 

 intermediate tropical oceans — that is to say, in the Indian Ocean, 

 but they have not yet been all recognized there. Only alalonga 

 is mentioned in Gilchrist's ' Catalogue of Fishes of South Africa ' 

 (Marine Inv. in S. Africa, Cape Depart. Agriculture, 1902). 



T. albacora is mentioned by Day among the fishes of India, 

 and by Bleeker as occurring at Batavia. 



Thynnus alalonga. (Text-fig. 3.) 



Orcynus alalonga Cuvier, Regne Anim. 1817. 



Thynnus alalonga Cuvier & Val. Hist. Nat. Poissons, vol. viii., 

 1831 ; Lowe, Supp. to Synopsis of Fishes of Madeira, Proc. Zool, 

 Soc. 1839 ; id. Trans. Zool. Soc. iii. 1849. 



Germo alalonga Jordan & Evermann, Fishes of North and 

 Middle America, Bull. U.S. National Museum, No. 47. 



Albacora alalonga Dresslar & Fesler, Review of Mackerels of 

 America and Europe, Bull. U.S. Fish. Comm. for 1887, 1889. 



Orcynus germo Kitahara. Scombridas of Japan, Jo urn. Fish. 

 Bur. Tokyo, vol. vi., 1897. 



Germo germo Jordan & Seale, Fishes of Samoa, Bull. U.S. Bur. 

 Fish. vol. xxv., 1905. 



Scaled all over. General appearance silvery with scarcely any 

 yellow colour on dorsal and ventral tins, a trace of it in the middle 



Text-fio-. 3. 



Thynnus alalonga, 3 ft. 2£ in. long. From a photograph by the Author. 



of the dorsal finlets, none on the ventral. Second dorsal and first 

 ventral scarcely higher than first dorsal, with no yellow colour. 

 Pectoral very long, narrow, pointed, scythe-shaped, reaching to 

 posterior border of first ventral fin and fitting into depression on 



