. Bulletin - United States National Museum. Science. PACIFIC TUNICATA OF NATIONAL MUSEUM 81. Figure 26.— Trididemnum savignii (Herdman): Colony collected off NomasakI, Japan. of rays on equatorial plane varies from 6 to 8 in Japanese specimens to 10-15 (about 13 on an average) in the Hawaiian specimen, although generally fluctuating between 8 and 12. Density of spicules differs considerably according to colonies, generally speaking they are not particularly dense in any colonies of the present material. They are evenly distributed throughout the test from the bottom to the surface in most
. Bulletin - United States National Museum. Science. PACIFIC TUNICATA OF NATIONAL MUSEUM 81. Figure 26.— Trididemnum savignii (Herdman): Colony collected off NomasakI, Japan. of rays on equatorial plane varies from 6 to 8 in Japanese specimens to 10-15 (about 13 on an average) in the Hawaiian specimen, although generally fluctuating between 8 and 12. Density of spicules differs considerably according to colonies, generally speaking they are not particularly dense in any colonies of the present material. They are evenly distributed throughout the test from the bottom to the surface in most colonies, while in two Japanese specimens they are found more densely around respective branchial apertures so that the apertures are seen as white spots to the naked eye. Size of zooid differs according to colonies; zooids rather small in some colonies, larger in others; thoraces may attain 550/a in a con- tracted state, abdomens up to 750/1, in length; thus distance between zooids becomes relatively large. Zooids colorless, yellowish white or pigmented dark greenish along the peripharyngeal band in some colonies. Branchial aperture 6-lobed, tip of atrial siphon also 6-lobed in some zooids. About 8 longitudinal muscles and a roundish thoracic organ containing minute spicules at level of second transverse vessel on each side of the thorax. Stigmata, 8-10 in each of three rows. One testicular follicle, sometimes bulb-shaped; proximal part of vas deferens usually coils 4 to 6 times or more (8 or 9) in Japanese specimens. Remarks.—Two Japanese specimens resemble very closely Didem- num {D?demm/7n) misaJciense (Oka & Willey) in the appearance of the colony and probably in color when they are alive. However, the structure of zooids differs distinctly from that of D. misakiense, and is of the typical Trididemnum, having three rows of stigmata. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - colorati
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