. Contributions to the natural history of the United States of America. Zoology; Chelonia (Genus); Ctenophora; Cnidaria; Animals. Chap. III. GENUS BOLINA. 257 almost straight to their termination, while those of the lateral ambulacra are arched over the two rounded parallel ridges which inclose the circumscribed area. It is easily ascertained, that eight narrow bands, similar to those observed in Pleuro- brachia, extend beyond the extremity of the ambulacra toward the central black speck, or rather toward the bulb under it, and that they are the prolongation of the vertical rows of locomotive
. Contributions to the natural history of the United States of America. Zoology; Chelonia (Genus); Ctenophora; Cnidaria; Animals. Chap. III. GENUS BOLINA. 257 almost straight to their termination, while those of the lateral ambulacra are arched over the two rounded parallel ridges which inclose the circumscribed area. It is easily ascertained, that eight narrow bands, similar to those observed in Pleuro- brachia, extend beyond the extremity of the ambulacra toward the central black speck, or rather toward the bulb under it, and that they are the prolongation of the vertical rows of locomotive flappers. Along the sides of the body the rows of locomotive flappers also gradually taper toward their actinal extremity, and, as soon as they reach the height of the dilatation of the lobes, the locomotive combs disappear, and the chymiferous tubes which accompany them can alone be traced fixrther. In the lateral amljulacra, however, the rows of locomotive flappers taper much sooner, and terminate at the base of the small lateral lobes, near their inner margin, for a considerable length above the actinal extremity of the ambulacra of the large lobes. In the small lobes we trace also a narrow prolongation of the chymiferous tubes of the lateral ambulacra, which extend beyond the locomotive fringes. The course of these narrow tubes in the lobes is very difficult to follow, and their connection with each other and with the central chymiferous cavit}' has been entirely overlooked by former observers, with the exception of Milne-Edwards; ^ though in the figures of Bolina elegans published by Mertens, there are already indications that he noticed the outline of their convolutions. I shall first trace the course of these tubes upon the larger lobes. As long as the tubes follow a straight course in the prolongation of the anterior and posterior aml^ulacra {Fig. 92 t), they remain at the surface of the lobes, covered only by the epidermis, beyond the ambulacra! rows themselves. But as
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