Anal opposite end of second dorsal, similar to it in form, but smaller, and about twice as high as long, its position half way between the ventrals and caudal. Its first spine is only about one-third as long as the second, which is two-thirds the height of fin; both concealed by the skin. Ventrals arising opposite second dorsal spine, about twice as high as wide, their inner margin with a small pointed lobe. Cartilaginous ridge on side of caudal peduncle moderate, highest anteriorly, its length half that of caudal lobe. Two slight oblique ridges behind the median ridge. Lateral line imperceptible in front of fourth dorsal spine, parallel with outline of back. No scales on head. Thoracic corselet of very large consolidated scales above pectoral, bordered by six rows of large distinct scales, which grow smaller from before backwards. Scales underneath ventrals and around other fins, similarly consolidated, and depressed under pectoral and ventral. Rest of scales nearly uniform in size. Teeth numerous, very small, in one row, the palatine dense and velvety. Rays of second dorsal and anal fins nearly hidden by adipose skin. Br. VI-VI D.XIV-12-|-8, P 32, V, I-8 A.II-8,-|-8 C.11-1-6-6-1-12. _Colors._—Above blackish, sides steel-blue, below silvery white, fins smoky, iris brown, finlets yellow edged with blue. The largest I saw measured thirty-three inches to fork of tail, and weighed twenty-five pounds. Numerous in summer among the islands off the southern coast of this State, and is said to occur as far north as San Luis Obispo. It affords excellent sport, being caught by trolling while sailing very rapidly, biting voraciously at a white rag. It is in my opinion the best fish for the table that is caught on this coast, but it is said to be sometimes poisonous. It belongs to the typical _Orcynus_ of Cuvier, distinguished from _Thynnus_, by the very long pectoral, eight pairs of finlets, small corselet, etc. The type of _Orcynus_ (Scomber alatunga, Linn., or O. alalonga, Duhamel), is called “Ala longa” (Long-wing) in the Mediterranean and resembles this species closely, but is figured as less high and with a smaller pectoral fin. This species is one of several confounded by sailors under the Spanish names of Albicore and Bonito. The English name Tunny is applied to an allied species on the coast of Europe, the _Thynnus vulgaris_, Cuv., and to its near representative the _T. secundi-dorsalis_, Storer, of the eastern American coast. These, however, are evidently of a different genus, and as _Thynnus_ is preoccupied in insects, the name _Orcynus_, applied by Gill to the same type, may perhaps be retained, although _founded on a mistake_. _O. coretta_, Cuv. and Val., probably represents our species in the Gulf of Mexico.