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Show 74 ZOOLOGY OF THE VOYAGE OF THE BEAGLE. firm state of preservation, it is hardly possible to say whether they are. new or not. I n fio rm, they differ but little from the P. cyan. opltrys d of Cuvte·r ta ndf Valenciennes : still they are evidently not tha~ speetes, an one pom o difference consists in the lateral line, which termmates beneath .the end of the second dorsal, and is not carried on to the caudal, as represented m the figure of t h e a b ove spect·e s 1'n the " Histoire des Poissons :" the eye too appears rather larger ; t h e fio re h ea d I·S hardly so much elevated, and the pectorals are sh 11 ortehr than the head. Perhaps it may be the P. leucurus of the above aut.hors ; t .oug t hI. S speci·e s I·S f rom the Indian seas , so that its range must be consi.d erabl,e .r f the same. The description of the p. leucurus in the " His to ire des P01ssons ISf t'o o short to determine this point. It is said to have been so named o? account o tts whitish tail, all the other fins being black. In the present spec1es, t~e.fin~ are likewise black, or at least dusky, except the caudal, which Mr. Darwm s notes, taken from the recent fish, state to have had" a pin~ tinge." In. the sa~e no~es it is added,·-" belly silvery white mottled with browmsh black ;. sides blmsh wtth dusky greenish markings; iris yellow, with dark blue pupil." The fin-ray formula is as follows : D. 10-1{27; A. 3f27; C. 17, &c.; P. 17 or 18; V. 1/5. Though these specimens are small, they have the appearance of being nearly full-sized. Cuvier and Valenciennes state that their specimens of the P. leucurus do not exceed two inches in length. STROMATEUS MACULATus. Cuv. et Val.? Stromateus macula.tus, Ouv. et Val. Hiijt, des Pois3. tom. ix. p. 296. FoaM. -General form so extremely similar to that of the S. Fiatola of the Mediterranean as to preclude the necessity of a detailed description. Greatest depth one-third of the length : he~d one-fifth of the same. Number of rays in the dorsal and anal fins somewhat greater than m the S. Fiatola. The height of the dorsal also a little greater, being contained about three times and a half in the depth: the fifth and sixth soft rays longest. Fleshy part of the tail tnore slender. Pectorals about the length of the head. B. 6; D. 7/41; A. 5/40; C.17, besides several short; P. 23; V. 0. Length 8 inches 6 lines. CoLOUR.-" Silvery blue above, with regular circular leaden spots."-D. The spots are small, and of nearly equal size: they prevail from the back downwards to about the middle of the depth, and advance a little on the base of the dorsal fin. The arrangement of them is much as described in the "Histoire des Poissons." Habitat, Chiloe, West Coast of S. America. It is just possible that this may not be specifically the same as the S. maculatus of Cuvier and Valenciennes, but it comes so extremely near that species that I do FISH. 75 not feel authorised in describing it as distinct without seeing more specimens. It is stated by the authors above mentioned, that the fin-ray formula of the S. rnaculatus is the same as that of the S. Fiatola: in the specimen here described, the number of rays in the dorsal and anal fins appear to me somewhat greater ; but as the spines of these fins are very minute at their commencement, and not readily counted, nor very distinguishable from the soft rays, perhaps the discrepancy may arise from a difference in the mode of computation. What is more to be noted is, that the spots, although they agree in form and mode of arrangement, are said by Mr. Darwin, in his notes taken from the recent fish, to have been "leaden;" whereas it is stated in the " Histoire des Poissons" that they are "yellow." Perhaps they may vary in colour according to the period of the year. There is likewise a difference in locality as regards latitude. The S. maculatus is said to be common in the market at Lima, and to have been brought also, both by M. D'Orbigny and M. Gay, from Valparaiso. Mr. Darwin's specimen, however, was taken as far south on the western coast of S. America as Chiloe. Mr. Darwin's collection contains another specimen, either of the same species as that described above, or one so extremely similar to it as not to be distinguishable in the case of this specimen, which is in too bad preservation to admit of an accurate description of it being given. The following, however, are Mr. Darwin's notes taken from the recent fish:- CoLoun.-" Whole body silvery; upper part of the back iridescent blue, lower greenish ; spotted with coppery-lead circular patches."-D. This specimen measures ten inches and a halfin length. It will be observed that the colour of the spots is still said to have been "lead," though inclining to coppery. It was not taken at the same place as the other, but at Port St. Julian, in central Patagonia; if therefore they are both referable to the S. maculatus, this species will have been proved to have a wide range in point of latitude, and also to occur on both sides of the S. American Continent, which is remarkable, considering that it is found so high up the western side as Lima. FAMILY.-TEUTHYDIDlE. 1. AcANTHunus TRIOSTEGus. Bl. Scltn. Aca.nthurus triostcgus, Ozev. et Val. !list. des Poiss. tom. x. p. 144. --- Hirudo, Benn. Fish of Ceyl. pl. xi. This species, which appears to be well known, and to have been described by several authors, was found by Mr. Darwin on coral reefs at the Keeling Islands. Cuvier and Valenciennes observe that it has a wide range through the Indian and |