. Bulletin - United States National Museum. Science. ASCIDIANS OF THE PHILIPPINES VAN NAME. 143 the sides of the colony, but with less obvious regularity on the top. The common cloacal ducts run vertically between every second row of zooids and probably all converge to one common cloacal aperture on the top of the colony. Zooids small (not usually over mm. long in the preserved state) ; the largest and oldest are in the upper part of the colony. Branchial aperture small, often only slightly prominent; unlobed. Atrial aperture a large opening whose anterior border may be pro- duced into a
. Bulletin - United States National Museum. Science. ASCIDIANS OF THE PHILIPPINES VAN NAME. 143 the sides of the colony, but with less obvious regularity on the top. The common cloacal ducts run vertically between every second row of zooids and probably all converge to one common cloacal aperture on the top of the colony. Zooids small (not usually over mm. long in the preserved state) ; the largest and oldest are in the upper part of the colony. Branchial aperture small, often only slightly prominent; unlobed. Atrial aperture a large opening whose anterior border may be pro- duced into a short languet. Mantle thin and transparent. Its musculature is only slightly developed and is mostly confined to the thorax, being composed chiefly of very delicate bands having a transverse or oblique direc- tion or encircling the apertures, but these bands are few and very slender. Only eight tentacles of two sizes, placed alter- nately, could be demonstrated with certainty. Dorsal languets rather small, arising from the transverse vessels a little to the left of the median dorsal vessel. Branchial sac large, with four rows of stigmata. The rows are arranged in pairs, the first and second sepa- rated only by a narrow trans- verse vessel, and the third and fourth rows also, while be- tween the second and third rows a wider vessel intervenes. There are 14 or 15 stigmata in a row on each side in the two anterior rows and one or two less in the posterior ones. Intestinal loop small; generally not twisted. Stomach small, pear shaped, tapering toward the pyloric end, and smooth walled. Margin of anus slightly two lipped. Only female reproductive organs were found, though many zooids were examined, and these were not greatly developed. They con- sist of a saclike ovary containing a few eggs lying in the dorsal region of the abdomen close against the ascending part of the intes- tinal loop. The largest eggs are in the posterior part of the ovary; the anterior end of the latter appear
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