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Show 16 ZOOLOGY OF THE YOYAGE OF TilE BEAGLE. of the pectoral , which appears to be a character of so~e im~ortanc~, and whi~h ha led to the generic name of .Aplodactglus, amounts m th1s specrmen to SIX, bein()' two more than was ob·erved by 1\'I. Valenciennes in his, though the total 0 . number of ray in this fin i, the same. I may also allude to the circumstance of the dorsal being inve·ted ut the base with a thickened membrane on each side, do ely covered with mall cale , which extends over nearly its whole length, but i mo t conspicuou along the spinous portion. This character is not mentioned by M. Valenciennes. .,. either does he mention the rows of minute scale~, ~bich occur between the rays of all the fins, except the ventrals. Mr. Darwin' pecimen of this fish is eleven inches in length. The following i - the fin-my formula: B. 6; D. 15-1/21; A. 3/8; C. 17. &c.; P. 9- vi; V. l f5. l. DuLES AuRIGA. Cu;c. et Val. Dul Auri!!:L. Cue. tt Val. Hist. <1 'Poi.ss. tom. iii. p. 3. pL 51. Fo.R.M.-Th' · pecies · remark ble for the prolongation of the third dorsal spine, which, in the present pecimen, is not quite equ:ll to half the entire length of the head and body; a small portion, however, appears to have been broken off. The greatest depth is contained three and a half times in the entire length. The head, measured to the extremity of the opercular membrane, e ctly equ ls the depth. The line of the profile is not quite straight, there being a ~light depression at the nape, above which is a con..-e.:city in immediate advunce of the dorsal tin. Tne lower jaw is a very little the longest. The eyes are large ; and the distance between them barely equals their diameter. The other characters are exactly as stated in the '' Hi,;toire de · Pois::ons." B. 6; D. 10/13; A. 17; C. 17; P. 17; V. t /5. Length ~ inches 3 lines. CoLo tnt.-The recent colours are given by l\Ir. Darwin in his notes as follows ~ '' ides with numerous waring longitudinal lines of brownish red; the intermediate p ces greeni, h- il very, o figured as to look mottled. Head marked with lines of dull red and green. Ventral and anal fins dark. ~reen1:;h bLue."-He d s not notice the vertic:ll - alluded to by Curier a.nd V lenciennes, hich re ~llfiiciently obvio -,and which accord with the 1\,<TUre nd description of the autho~ ju.->t mec.tioned. H. bit t, Maldonado Bay, Rio Pl t . FISH. 2. DuLES LEucxscus. Jen. Dules malo, Val. ? Ilist. des Poiss. tom. vii. p. 360. D. pinnis caudali, anali, dorsalique molli, nigro-marginatis; dorsali profunde emarginatd, spind ultimd mdiis a1·ticulatis hreviore; operculo mucronibus duohus, infe- 1'iore maximo, w·mato; preoperculo margine adscendenti levissinte denticulato, hasali denticulis fortioribus. B. 6; D. 10/11; A. 3/12; C. 16, &c.; P. 13; V. I/5. LoNG. unc. 4. lin. 5. FoRM.-General form resembling that of a small Dace. Greatest depth about one-third of the entire length, caudal excluded. Length of the head rather less. Dorsal line falling with the profile in one continuous gentle curve. Eyes large ; their diameter contained two and n half times in the length of the head: the distance between them less than one diameter. Suborbitals finely but very conspicuously denticulated. Jaws nearly equal; the lower one a little the longest. In each, a band of velutine teeth, with the outer row rather longer than the others. Opcrcle with two points, the lower one most developed. Preopercle with the limb striated : the ascending margin with the denticulations so fine as to be hardly sensible to the naked eye; those on the basal margin larger and more obvious. Scales of a moderate size; about forty-three in a longitudinal row; their free portions finely striated. Cheeks and opercle scaly; crown naked, with a shallow groove above each eye. Lateral line at first slightly descending, but afterwards straight; its course, until past the dorsal and anal fins, a little above the middle of the depth. Dorsal deeply notched : the anterior portion consisting of nine spines ; the first very short, and scarcely more than half the length of the second; third and fourth longer, increasing gradually; fifth and sixth equal and longest, equalling half the depth of the body; seventh, eighth, and ninth, shorter, and gradually decreasing ; the tenth spine, with which the second portion of the fin commences, is of the same length as the fifth, but not quite so long as the soft rays which follow; these soft rays, however, gradually become shorter, the last two not more than equalling the second spinous. The whole space occupied by the dorsal is more than one-third of the entire length. Anal commencing in a line with the ninth dorsal spine; its own three spines gradually increasing in length, but the second the strongest; soft portion of this fin longer than the corresponding portion of the dorsal, and terminating a little nearer the caudal. Vent in a line with the seventh dorsal spine. Pectorals small, reaching to the vent. Ventrals attached a little further back, and reaching a very little beyond it. Caudal forked. CoLOUR.-( In spirits.) Silvery, tinged on the back, and above the lateral line, with bluish grey, and somewhat mottled in places with darker spots. Fins yellowish-grey, tinged with dusky. The caudal, anal, and soft portion of the dorsal, are a little mottled with dusky, besides having a black edging ; there is al so a conspicuous black spot at the anterior angle of this last fin. v |