. Chimæroid fishes and their development. Fishes; Chimaeridae. ^g which Fig. 81. -Transverse section passing through the otic vesicles of preceding embryo. sides external gills are shown. 'I, artery; (/, dilated blood knot in external gill; s, spiracle; V, vein. At the tig. 50", m wmcn we note that in each fila- ment one of the compo- nent vessels is less con- torted than its neigh- bor, the filament thus presenting a crinkly appearance when viewed under a low power. Occasionally a terminal dilatation is seen. It will be noted that some of the filaments attain great length, although in ge
. Chimæroid fishes and their development. Fishes; Chimaeridae. ^g which Fig. 81. -Transverse section passing through the otic vesicles of preceding embryo. sides external gills are shown. 'I, artery; (/, dilated blood knot in external gill; s, spiracle; V, vein. At the tig. 50", m wmcn we note that in each fila- ment one of the compo- nent vessels is less con- torted than its neigh- bor, the filament thus presenting a crinkly appearance when viewed under a low power. Occasionally a terminal dilatation is seen. It will be noted that some of the filaments attain great length, although in general the}^ are fewer in this than in the earlier stage, a process of reduction having set in at certain points.* In lateral view this embryo shows fragments of yolk attached to its side and to its paired fins, a condition probably artifact, although deserving mention, since in the younger stage yolk masses were observed attached to the gills. Before making the present sketch, a portion of the opercular fold and the neighboring external filaments were removed. The sensor}' canals are well indicated; that of the lateral line has now passed down the side of the body and has entered the tail region. The mandible is well established. In plate IX, fig. 50'^, we observe the extent to which the opercular folds overlap the tuft of external filaments; we here observe also that the frontal clasping organ *cy. also Schauinsland {op. cit., Taf. xvi).. 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 Dean, Bashford, 1867-1928. Washington, D. C. , Carnegie Institution of Washington
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectfishes, bookyear1906
