. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 286 TORRE Y. [VOL. spirals of the lophophore there are one and one-half to two, and a correspondingly smaller number of tentacles (170-200), Fig. r, A, B. In the strength of its longitudi- nal muscles (Figs. 2,3) it departs and even surpasses P. architecta, resembling the latter species in the possession of a specialized ridge in the digestive tract (though this does not pass into the groove that Andrews describes), in the structure of the nervous sys- tem, lophophore organ and tube, in habit, and in the po
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 286 TORRE Y. [VOL. spirals of the lophophore there are one and one-half to two, and a correspondingly smaller number of tentacles (170-200), Fig. r, A, B. In the strength of its longitudi- nal muscles (Figs. 2,3) it departs and even surpasses P. architecta, resembling the latter species in the possession of a specialized ridge in the digestive tract (though this does not pass into the groove that Andrews describes), in the structure of the nervous sys- tem, lophophore organ and tube, in habit, and in the possible separation of the sexes. It is not my intention to enter into a full and detailed anatomical description of Phoro- nis, which the labors of Benham and Cori have rendered largely unnecessary. But a few words on some points may not be out of place. In one of the Puget Sound specimens sper- matogonia and sperma- tocytes were found packed around the blood vessels in the aboral regions of the body, but no spermatozoa nor ova. The aboral ends of all the Humboldt specimens were wanting, so it was impossible to deter- mine whether they were monoecious or dioecious. In one nephridium three ova were found unaccompanied by sperma- tozoa ; the first polar body was forming in one. As there was no sign of sperma- tozoa in these eggs, it is probable that in this species fertilization takes place either externally or within the nephridium. It is quite possible that the sexes may be separate, or ova and sperm may be produced by the same individual but not simultaneously. The blood corpuscles have a conspicuous yellow color and measure 10-15^ in diameter. '•«N FIG. 3. —Cross-section of one longitudinal. 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 Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biolog
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
