. The Cambridge natural history. Zoology. FiG. 105.—Cycloid scale of Scdmofario. Fio. 106.—A, Ctenoid scale; B, "Ganoid" a. Anterior portion covered by overlap scale. (After Gunther ; from Parker and of preceding scales ; b, free portion Haswell.) covered only by pigmented epidermis. (From Parlier and Haswell.) thidae ( Malthe ^) have similar scales, but with round basal plates and solid spines (Fig. 108, B). Similar scales (Fig. 109), sometimes rhombic in shape, with one or more spines, which may be simple or branched, are also found in the Sclerodermi ( Balistes, Monacantlu
. The Cambridge natural history. Zoology. FiG. 105.—Cycloid scale of Scdmofario. Fio. 106.—A, Ctenoid scale; B, "Ganoid" a. Anterior portion covered by overlap scale. (After Gunther ; from Parker and of preceding scales ; b, free portion Haswell.) covered only by pigmented epidermis. (From Parlier and Haswell.) thidae ( Malthe ^) have similar scales, but with round basal plates and solid spines (Fig. 108, B). Similar scales (Fig. 109), sometimes rhombic in shape, with one or more spines, which may be simple or branched, are also found in the Sclerodermi ( Balistes, Monacantluis, Tria- canthus)? Amongst some of the usually scaleless Siluroid Fishes the scales assume a very peculiar structure. In Hypostoma^ (Fleco- stomus) the sides and back of the Fish are covered by large bony plates, but on the under surface and on the fins these are replaced by much smaller ones. Both kinds, however, carry numerous small movable spines implanted in sockets (Fig. 110), a fact which suggests comparison with a stage in the de- velopment of the scales oiZepidosteus, when the lopax. A, Scale from independently formed and evanescent spines soVBl'^ri^Zmthe ^^^^ ^°* ^^^ ^""'^^ ^^^h the_ basal plates. base of the pectoral In other Tcleosts, as in the Agonidae He'rtwigT' *^'™ ^""^ some Triglidac, the body is completely cuirassed with large keeled bony plates. The singular appearance of many of the Plectognathi is largely ^ 0. Hertwig, Morph. Jalirh. vii. p. 7. ' Ibid. vii. p. 29. ^ Ibid. ii. p. 334. Fig. 107.—Centriscus sco-. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Harmer, S. F. (Sidney Frederic), Sir, 1862- ed; Shipley, A. E. (Arthur Everett), Sir, 1861-1927. ed. [London, Macmillan and Co. , Limited; New York, The Macmillan Company
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1895
