The runner, _Elegatis bipinnulatus_, differs from _Seriola_ in having a finlet behind dorsal and anal. It is found in almost all warm seas, ranging north once in a while to Long Island. The mackerel scads (_Decapterus_) have also a finlet, and on the posterior part of the body the lateral line is shielded with bony plates. In size and form these little fishes much resemble small mackerel, and they are much valued as food wherever abundant. _Decapterus punclatus_, known also as cigar-fish and round-robin, frequently visits our Atlantic coasts from the West Indies, where it is abundant. _Decapterus russelli_ is the _Maruaji_, highly valued in Japan for its abundance, while _Decapterus muroadsi_ is the Japanese muroaji. [Illustration: FIG. 215.—The Saurel, _Trachurus trachurus_ (Linnæus). Newport, R. I. ] _Megalaspis cordyla_ abounds in the East Indies and Polynesia. It has many finlets, and the bony plates on the lateral line are developed to an extraordinary degree. In _Trachurus_ the finlets are lost and the bony plates extend the whole length of the lateral line. The species known as saurel and wrongly called horse-mackerel are closely related and some of them very widely distributed. _Trachurus trachurus_ common in Europe, extends to Japan where it is the abundant maaji. _Trachurus mediterraneus_ is common in southern Europe and _Trachurus symmetricus_ in California. _Trachurus picturatus_ of Madeira is much the same as the last named, and there is much question as to the right names and proper limits of all these species. In _Trachurops_ the bony plates are lacking on the anterior half of the body, and there is a peculiar nick and projection on the lower part of the anterior edge of the shoulder-girdle. _Trachurops crumenophthalma_, the goggler, or big-eyed scad, ranges widely in the open sea and at Hawaii, as the _Akule_, is the most highly valued because most abundant of the migratory fishes. At Samoa it is equally abundant, the name being here _Atule_. _Trachurops torva_ is the meaji, or big-eyed scad, of the Japanese, always abundant. [Illustration: FIG. 216.—Yellow Mackerel, _Carangus chrysos_ (Mitchill). Wood's Hole. ]