(JHEATKU SCOPKI.US. 



939 



Ikiiic. TIhti' is no 1nu! tongue, but tlio cartihiginous 

 tj|i 1)1' the liiijiu.'il hone is rather high and pi'oinincnt 

 rjii'lit in till' ;ini;ic lictwccn the braiieiies of tli<' lower 

 JMW. Here the h\'oi<l arch of each side is nitached, 

 and just behind it the first branchial arch, the inferior 

 part of which is so long that it extends behind the 

 branches of the lower jaw. The anterior gill-slits are 

 also ver\- large; but the last (fourth) branchinl arch, 

 with onh' one row of lamelhr, is united throughout 

 the greater part of its length to the shoulder-girdle, 

 the hindmost gill-slit thus being quite short and open 

 only below. The gill-rakers are setiforiu. The outer 

 row on the first braiiciiial arch contains aliout 25 gill- 

 rakei's, 17 of them belong to the lower, front part of 

 the arch. The pseudobranchia? consist of a longitudinal 

 row containing about 22 transversely set, filamentous 

 lamella- on the inner, upper surface of the hyomandi- 

 bular bone. The opercular apparatus is considerably 

 prolongated in a backward direction. The preoperculum, 

 which has no lower (forward, horizontal) arm, lies, as 

 in the Anchovy, in an oblique, back\vard and down- 

 ward direction. Behind, this bone expands into a thin, 

 dermatoid, membranous margin, which lies over the an- 

 terior part both of the operculum and the suboperculum, 

 and this membranous margin is covered with scales 

 pierced by a branch of the lateral line. The shape of 

 the quadrangular operculum is adapted to that of the 

 jireoperculum, the former Ijeing also oblique, rhombic, 

 and obliquely set, in the same direction as the preoper- 

 culum. The hind extremity of the opercular apparatus 

 is formed by the upper posterior corner of the trian- 

 gular suboperculum, the lower posterior side of which 

 is indented, and at the lower angle of which lies the 

 small, rounded, and scale-shaped interopereulum. The 

 black branchiostegal membrane of each side is entirely 

 separate from that of the other side, but is closely ap- 

 plied and united by connective tissue to the inner sur- 

 face of the branch of the lower jaw, thus forming, as it 

 were, a lining thereof, and hardly projecting beyond its 

 margin. The eight slender branchiostegal rays increase 

 in length backwards, but are comparatively short. On 

 the hyoid arch lie the three luminous spots that shine 

 through the branch of the lower jaw, the first at the 

 base of the foremost three rays, the second on the space 

 between the fifth and sixth rays, and the third on the 

 membrane between the bases of the seventh and eighth 

 rays. The gill-opening on each side extends upwards 

 beyond the superior margin of the operculum, and the 



distance from the tip of the snout to the upper angle 

 of each gill-opening is equal to the postorbital length 

 of the head. 



The true dorsal fin is I'ather large and of a quad- 

 rangular shape, with undulating upper posterior margin. 

 The tin begins at a distance from the tip of the snout 

 measuring about 38 % of the length of the body. The 

 length ol' its base is about 28 %, and that of its longest 

 ray (the fourth or fifth) about 18 ?», of the length of 

 the body. The first four rays are sinqde — the first 

 ray, which is very small, also unarticulated. Among 

 the remaining rays the anterior (13 or 14) are branched 

 only once and at the tip, the posteu'ior (6 or 5) twice 

 and more deep]}'. The adipose fin, which is short but 

 rather high, only slightly lower than the hindmost dorsal 

 rays, lies about half as far from the dorsal fin as from 

 the first upper supporting ray of the caudal. The anal 

 fin is similar in shapes and structure to the true dorsal, 

 but much shorter, with only three simple ra3s at the 

 beginning. The first ray is so small that it easily es- 

 capes attention, and the third is the longest in the whole 

 fin, or equal in length to the first branched ray. The 

 distance between the l)eginning of the anal fin and the 

 tip of the snout is about 54 %, and the base of the fin 

 measures about 20 %, of the length of the body, the 

 base thus terminating a little l)ehind the perpendicular 

 from the adipose fin. The height of the anal fin (the 

 length of the third or fourth ray) is about 1 6 ?o of the 

 length of the body. The caudal fin, which is deeply 

 forked, is remarkable in this species too for the short 

 but strong supporting ra^■s, true spinous rays, that arm 

 the dorsal and ventral margins of the tail in front of 

 the true base of the fin. In the only perfect specimen 

 within our reach there are both above and below 10 

 spinous rays, gradually increasing in length behind, and 

 2 articulated but simple rays, the first about one-third 

 as long as the second, wdiich extends nearly to the tip 

 of the fin-lobe. The remaining 16 rays are articulated 

 and branched, the middle ones about one-third as long 

 as the outermost, and measuring about 7 % of the length 

 of the body; but the base of the fin is covered at the 

 sides, at least half-way along the fin, with elongated 

 scales, concealing the roots of the rays. 



Among the ])aired fins the ])ectorals are jiointed. 

 shorter and narrower than the ventrals, which are rounded 

 and of average size. The length of the former is about 

 9 %, of the latter nearly 12 %, of that of the body. 

 The first (uppermost) ray in the pectoral fins is simple 



