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Show I I 10 ZOOLOGY OF THE VOYAGE OF THE BEAGLE. fifth of the entire length. Head contained three and a half times in th'e same. Profile sloping gradually from the commencement of the dorsal to the end of the ~nout in one co~tinuous.very gentle curve. The lower jaw a little the longest. The teeth are m str~ng card m both Jaws, t.heir points curving inwards and backwards: those above longest antenorly, where they form about three rows; posteriorly they become velutine, as in the last species, and consist of not more than two rows: in the lower jaw the teeth are equally large at the sides as in front, and, excepting quite at the anterior extremity, in only two rows, the inner of which ~s stronger than the outer. The canines are small, and scarcely stronger than the other teeth; m number* and situation, the same as in the S. labriformis. The vomerine and palatine teeth are very fine velutine. Eyes rather large, and high in the cheeks, equidistant from the upper angle of the preopercle and the intermaxillary, with a diameter about one-seventh the length of the head : the distance between them equals one diameter and one-third. The margin of the suborbital is entire, and nearly straight. The maxillary, when the mouth is closed, reaches to beneath the middle of the orbit. 'fhe nostrils are a little in advance of the eyes, and consist of one large, nearly circular, aperture, enclosing two smaller ones, which are also circular and placed equally in advance. Tile crown, and space between the eyes, and entire cheeks, are covered with small scales; there are also some minute ones on the lower jaw, and on the extremity of the snout before the eyes; but they are scarcely obvious, if present, on the first suborbital, and not at all perceptible on the maxillary. The preopercle is rather more than rectangular; the basal margin nearly straight and horizontal; the angle rather sharp ; the ascending margin with a slight sinuosity just above the angle, afterwards straight and nearly vertical, very obsoletely denticulated throughout its course. The osseous portion of the opercle terminates posteriorly in two flat points, nearly equal, but the lower one rather the more developed, between which it is emarginate. The angle of the membrane is considerably produced beyond the lower point. The line of separation between the opercle and subopercle is tolerably obvious. Gillopening large. All the pieces of the gill-cover are covered with scales scarcely smaller than those on the body. The scales on the body are not large, of an oblong form, with their free edges scarcely at all ciliated, not enough to feel rough to the touch ; their whole surface very finely striated, with twelve deeper stri~ on the basal half, and the basal margin crenated. Lateral line not very conspicuous, parallel to the back at about one-fourth of the depth. The dorsal commences in a line with the posterior angle of the opercle, and occupies a space equalling half the entire length, caudal excluded : ~:~pines strong, and tagged at their extremities ; the second longest, equalling not quite half the depth; third and succeeding ones gradually decreasing to the tenth, which is about half the length of the second; the eleventh again longer; then follow the soft rays, which are nearly even, but all higher than the last spinous. The anal commences in a line with the third soft ray in the dorsal, and terminates a little before that fin : first spine very short ; the third longest, but the second stoutest : of the soft rays the third and fourth are longest, and nearly twice the length of the third spine, being longer tl1an the soft rays in the dorsal; from the fourth they gradually decrease, giving this portion of the fin a rounded form. The caudal is nearly even, but the central rays are a little shorter than the outer ones. There are no rows of scales between the soft rays of the dorsal and anal, and • There are actu&lly only three below in this specimen, but there is little doubt of four being the normal number, one appearing to have been lost. FISH. II scarcely any trace of them between those of the caudal. The pectorals are rounded, attachecl low down, and about half the length of the head. V entrals directly beneath them, shorter, and more pointed. CoLOUR.-" Mottled brown."-D. The dried skin appears nearly of a uniform brown, simply a little paler beneath. There is some indication of a whitish band along the base of the anal and · soft dorsal, which may be the remains of a brighter colour. The base of the pectorals and ventrals is also paler than the extremity of those fins. Habitat, Galapagos Archipelago. This species was also obtained at Chatham Island, in the Galapagos, where Mr. Darwin states that it is common. In some of its characters it approaches the S. labriformis, but in others it is essentially different. It rather departs from most of the Serrani in the teeth, and in the small development of the canines. The nostrils also are rather peculiar. Perhaps it may one day be found to constitute the type of a distinct genus. PLECTUOPOMA PATACHONICA. Jen. P. opercula spmzs t1·ibus, intermedilt maximd; preopercztlo 'margine adscendenti denticulato; ad angulum dente unico, et ad ma1-ginem basalem dentibus duolms, fortibus; pinnd dorsali spinis quartd et quintd longissimis; pectomlibus radiorum apicibus e membrand paulo exeuntibus; caudali leviler 1·otundata. B. 7; D. 13/15 vel 16; A. 3/8 vel 9; C. 17i; P. 17; V. 1/5. LoNG. unc. 15. FoaM.-Greatest depth about one-third of the entire length, excluding caudal. Head rather exceeding one-third. Profile descending obliquely in nearly a straight line from the commencement of the dorsal to the end of the snout. Eyes large, high in the cheeks; their diameter nearly one-fourth of the length of the head. The lower jaw a little the longest: both it and the maxillary without scales. A band of velutine teeth in each jaw ; the outer row in card, with some, stronger than the others, which may be considered canines: above, the principal canines are about six in number on each side near the extremity ; below, there are three or four larger than the others similarly situated. The preopercle has the ascending margin distinctly denticulated ; on the basal margin are two strong teeth directed forwards, and a third at the angle. The opercle has three strong flattened spines i the middle one most developed. At the lower angle of the subopercle is a small flat moderately sharp point. Fourth and fifth dorsal spines longest; the succeeding ones gradually diminishing to half the height of the soft portion of the fin which follows. Second anal spine very stout. Pectorals with the tips of the rays slightly projecting beyond the membrane, giving it a festooned appearance. Caudal slightly rounded. |