ASCIDIANS OF THE PHILIPPINES VAN NAME. 127 



described on the same page of Herdman's article as R. crassa, but 

 following the Litter, the name crassa has priority if the identity of 

 the two forms is admitted. The references to R. fusca are as follows : 



1SS0. Ecteinascidia fusca Heedman, Proc. Roy. Soc. Edinburgh, vol. 10, 



p. 723. 

 1SS2. Ecteinascidia fusca Heedman, Rep. Voy. Challenger, vol. 6, Tunicata, 



p. 241, pi. 36, figs. 7-11. 

 1800. Rhopalopsis fusca Heedman, Proc. Liverpool Biol. Soc, vol. 5, p. 1G0. 

 1891. Rhopalopsis fusca Heedman, Journ. Linn. Soc. London Zool., vol. 



23, p. 601. 

 1S93-1907. Rhopalopsis fusca Seeligee, Bronn's Ttor-reich, vol. 3, suppl., 



pl. 37, fig. 8. 

 1S9S. Rhopalopsis fusca Heedman, Ann. Mag. Nat. Hist., ser. 7, vol. 1, p. 447. 

 1S99. Rhopalopsis fusca Heedman, Cat. Australian Mus., Sydney, No. 17, 



pp. 8 and 112. 

 1904. Rhopalopsis fusca Sltjiteb, Stfrof/u-Exped., vol. 56a, p. 13, pl. 2, fig. 6. 

 1909. Rhopalopsis fusca Haetmeyee, Bronn's Tier-reich, vol. 3, suppl., p. 



1418. 

 1912. Rhopalopsis fusca Haetmeyee, Deutsche Tiefsee-Exped., vol. 16, p. 373. 



All the specimens except one consist of a single isolated zooid, giv- 

 ing no indication of forming buds or of having developed by bud- 

 ding. The remaining specimen (pl. 28, fig. 14), consists of 3 zooids of 

 different sizes growing with their basal (posterior) ends near to- 

 gether and united by a continuous connection of test substance, 

 although the writer did not succeed in demonstrating a stolon con- 

 necting the zooids. 



Whether growing singly or united, each zooid is inclosed in its 

 own covering of test, which is of a yellowish or brownish yellow 

 color (greenish yellow in a formaldehyde specimen) and of a tough, 

 somewhat cartilagenous consistency, only slightly transparent or 

 merely translucent. The test is very thick, the cavity occupied by 

 the zooid's body often appearing very small in comparison ; the inner 

 layer immediately ensheathing the abdomen of the zooid is much 

 tougher and more rigid than elsewhere. Ordinarily the animal is 

 attached by the posterior end or more or less obliquely by that end 

 and a part of one side, sometimes by a large part of one side. The 

 test being of very irregular thickness, the external form is very 

 variable, but in the more regular specimens it is somewhat club- 

 shaped, the anterior end being often much swollen into a large 

 rounded knob-like head. The apertures are not prominent exter- 

 nally. Length of the largest specimen 45 mm., maximum width 

 about 19 mm., but some smaller ones are proportionally wider. 



When removed from the test the zooid has the typical form of a 

 compound ascidian, consisting of a thorax connected by a narrow 

 constricted region or neck with an abdomen of the usual oval form 

 containing the stomach, intestinal loop, and reproductive glands. 



