On the Changes of Form in Fishes. 107 Fig. 15. Parmula Batesii. Skeleton-spicule, to show the "abruptly-pointed " form. Fig. 16. Tuhella reticulata. Skeleton-spicule, to sliow " rounded end." Fig. 17. XJruguaya corallinides. Skeleton-spicule, to show micropuncta-tion and " rounded " ends. Fig. 18. Spongilla niteiis. Skeleton-spicule, to compare with foregoing form. Characteristic skeleton-spicules of freshwater sponges from Lake Baikal, after Dr.W. Dybowski ; traced off the figures in Taf. iv. (No. 32), drawn with Hartnack's prism and no. 4 objective. Fig. 19. Luhomirskia haicalensis, Pallas : a, " parenchyma-spicule," after Dybowski. Fig, 20. L. bacillifera, n. sp. Fig. 21. L. intermedia, n. sp. Fig. 22. L. pajn/racca, n. sp., two forms. X. — Spolia Atlantica : Contrihutions to the Knoioledge of the Changes of Form in Fishes during their Growth and Development, especially in the Pelagic Fishes of the At-lantic. By Dr. C. F. Lutken. [Continued from p. 14.] 8. Beama, Taeactes, Pteeycombus, Pteeaclis. With regard to Brama, it is to be remarked, in the first place, that it has been ascertained that B. Raji is not an almost exclusively Mediterranean species, but a bathyphilous and very cosmopolitan species, which is spread from the Faroes to the Cape, and represented at Chili, New Zealand, and Japan by very nearly allied, if not identical forms {B. japonica, Hilg., appears to be a distinct species), but has not yet been found among the Antilles or on the eastern coast of America. Leaving out of consideration some young forms {B. Orcini, B. Dussumieri) which cannot pretend to the rank of distinct species, a series of species from the Antilles, Madeira, &c. have subsequently been described, some with smooth scales, others, as in Pteraclis and Pterycombus, with a large spine upon the anterior margin of the visible part of each scale, and a corresponding notch in the posterior margin of the immediately preceding scale. It is a singular thing that it has not hitherto been observed that B. Raji, when young but yet about half-grown (290 millims.), has the scales armed with the same spines, which do not disappear until the fish approaches its full development. We are therefore not justified in forming a separate genus ( Taractes) for the species of Brama with spines, nor in determining the young individuals furnished with spines {Taractes asper, Brama Orcini and
X.—Spolia Atlantica: Contributions to the knowledge of the changes of form in fishes during their growth and development, especially in the pelagic fishes of the Atlantic
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