72 COHVPII.EN'ID.E. 



Although the mouth when closed seems small, the crape is laro;o, the commis- 

 sm'e remarkably oblique, and with a crooked or distorted appearance. The max- 

 illaries are narrow and slender, reaching to a point below the middle of the eye. 

 The lower jaw is longer than the upper : both are furnished, in front, with a 

 broad band of rather strong and sharp, but brush-like teeth, reaching to tlie 

 corners in the lower jaw, and growing nan'ower backwards ; but reduced almost to 

 a single row on the sides of the upper jaw ; which has also a round patch on the 

 vomer, and a short and narrow band of similar teeth upon each palatine. The 

 tongue is free, broad, rounded, with a large square patch of brush-like teeth in the 

 middle, and the edges or border in front and on the sides remarkably thin and 

 smooth. 



The preopercle is peculiarly plain and flat, of a naiTOW parabolic shape, 

 directed obliquely downwards. The opercle forms with the interopercle, which 

 is rather broad, a wider parabolic curve outside the former : it has a slight notch 

 or sinus near the top. A few diverging striae radiate from the articulation of the 

 opercle with the frontal bone, partly over its upper end. Otherwise the whole 

 three are smooth, unarmed, and even ; with entire edges. 



The branchial opening is large, its membrane prominent, with the edge broadly 

 scalloped. Its six upper rays are flat, and very strong and broad : the first or 

 lowest weak, and difficult to find ; being not flattened like the rest, and concealed 

 l>eneath the second. 



The whole head, muzzle, lower jaw and opercles, with the exception of a scaly 

 patch upon the cheeks beneath and behind the eye, are perfectly naked, and covered 

 with a smooth and even skin. The whole has a remarkably plain compact ap- 

 pearance, such as indeed is usual in the swift pelagic fishes. There is no pecu- 

 liarity observable externally about the superscapulary and humeral bones, on the 

 shoulders, or at the axils of the pectoral fins. 



The lateral line forms generally an abrupt festoon above the middle of the 

 pectoral fins ; beyond which, after a little irregular waving, it continues straight, 

 and in the middle of the body, to the end. 



The scales, beginning on the nape at the origin of the dorsal fin, are extremely 

 small and inconspicuous, oblong or trapeziform, somewhat cuneate or bi'oader at 

 the outer or hinder end, finely striate concentrically like the lines at the ends of 

 the fingers, but otherwise smooth and almost membranous. They extend far up 

 between the rays of the caudal fin ; but all the other fins are smooth and naked. 



The dorsal fin begins very forward on the nape ; a vertical line from the base 

 of its first ray falling, however, perfectly clear of the hinder edge of the orbit. It 

 is highest in front, in a line with the edge of the opercle, or base of the pectoral 

 fins ; and from a little behind this point it gradually lowers off', rising again a 

 little towards the end. The first rays are very short and crowded, and so buried 

 in the thick leathery elastic skin or web that they are difficult to count ; but they 

 gradually increase in length to the eighth ray, to which the following ten or 

 twelve are nearly equal. The anterior rays are simple ; the hinder become 

 gradually more branched, as well as more remote, and their tips protrude beyond 

 the web : but all are of the same flexible elastic substance, like whalebone ; 

 differing equally from the spines, as from the branched articulated rays of most 

 fishes. Its greatest height in front scarcely equals half the depth of the body 

 below it, and is one sixth or seventh part of the length of its own base ; at the 

 hinder end it is scarcely half this height in front. 



The anal fin begins opposite the thirty-fourth ray of the dorsal, which it re- 

 sembles in shape ; in structure corresponding with its hinder half The elevated 

 part in front, however, is not so much rounded oft", but more abrupt or angular, 

 and scarcely equals the height of the hinder end of the dorsal fin. The first ray 



