. The fur seals and fur-seal islands of the North Pacific ocean. Sealing; Seals (Animals). TUNICATA OP THE PRIBILOF ISLANDS. 619 It-. colony. (Fig. 14, area B, exaggerates the distinctness of the branchial orifices.) The common cloacal appertares wholly obliterated to superficial inspection. Branchial siphon found, after isolation of zooids, to be six lobed. Atrial siphon with a broad' languet the distal edge of which is armed with three small processes (fig. 16). Branchial tentacles about 24 in number, rather large, though a few small; not forming a well-defined single circle. Eather close to
. The fur seals and fur-seal islands of the North Pacific ocean. Sealing; Seals (Animals). TUNICATA OP THE PRIBILOF ISLANDS. 619 It-. colony. (Fig. 14, area B, exaggerates the distinctness of the branchial orifices.) The common cloacal appertares wholly obliterated to superficial inspection. Branchial siphon found, after isolation of zooids, to be six lobed. Atrial siphon with a broad' languet the distal edge of which is armed with three small processes (fig. 16). Branchial tentacles about 24 in number, rather large, though a few small; not forming a well-defined single circle. Eather close to the branchial orifice. Branchial sac well developed. About 15 series of stigmata and about 16 stig- mata in each half series; these very regular in form and size. The interserial vessels broad and each containing a well-devel- oped muscle band. (Fig. 15, m. e. v.) Dorsal languets long and slender, about one for each series of stigmata. Digestive tract,—CEsophagus (fig. 15 ce) issuing posterio- dorsally from the branchial sac, longer than the stomach; deflected to the right side by the rectum. Stomach spherical, smooth walled both without and within. Duodenal portion of the intestine with two well-marked constrictions. Eectaf por- tion large and straight, runs far forward, nearly in the median dorsal line, which it reaches by a left curvature of the duo- denal portion. (Fig. 15.) Sexual organs.—Gonads contained in the large pear-shaped pedunculated postabdomen; ovary a well-defined mass, confined to the enlarged posterior portion of the postabdomen. (Fig. 16, ov.) The ova pass into the atrial chamber, where they take a position in its posterior portion and to the right side. The larvae are developed in this incubatory chamber. No male gonads have been found in any of the specimens examined. No buds have been seen; and as the colonies at hand are all in a state of prolific sexual reproduction, it seems probable that in this species there is an alternation of periods of sexua
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Keywords: ., bookcentury1800, bookdecade1890, bookpublisherwashingtongovtprin
