CATALOGUE OP TUNICATA. O 



fairly large, and are arranged with regularity. There are no internal 

 longitudinal bars, and no papilliform processes on the horizontal 

 membranes. 



Dorsal languets are present. They are long and pointed, and are not 

 united at their bases. 



The tentacles are numerous and slender, placed in one row. 



The viscera form a large opaque mass, longer than the thorax, and of 

 nearly cylindrical form, the stomach forming no marked enlargement. 

 The rectum is very long. 



Locality. Port Jackson. 



This form (PL Clav. II., fig. 1) has a superficial resemblance to some 

 Compound Ascidians of the genus Colella, where the body is placed 

 on the summit of a long slender horny stalk." The lower end of the 

 stalk is expanded, and gives off root-like prolongations. The viscera 

 and mantle are of a dark purplish colour, which shows through the thin 

 grey test. There is a central cavity continued down the stalk, which 

 probably contained a tubular prolongation from the body similar to that 

 which is found in the stolon of Clavelina. It has, however, in these 

 specimens been retracted and torn, no doubt as a result of the mode 

 of killing and preservation, so as to lose its connection with the body 

 proper, but its remains are to be found adhering to the walls of the 

 tube. The branchial and atrial apertures are on small papillae placed 

 not far apart. The mantle is full of dark purplish pigment corpuscles, 

 which make it quite opaque ; the branchial and atrial siphons are 

 especially dark-coloured. The branchial sac is large and has numerous 

 stigmata. The horizontal membranes are especially wide (PI. Clav. II., 

 fig. 4). 



Dr. Sluiter, in describing the Tunicata collected by Prof. Semon at 

 Amboina and Thursday Island, came upon a form which he suspected 

 to be this species. So, before describing it, he courteously consulted 

 me on the matter, and sent me drawings. I had little difficulty in 

 recognising that his specimen belonged to my species, and now that 

 Sluiter's full account has been published,! I am still of the same 

 opinion, notwithstanding a few slight differences in our descriptions and 

 figures. These, I think, do not exceed the limits of individual variation. 



* See Herdman. "Challenger" Report, Ft. II., p. 72. See the species of Colella, 

 figured further on in this Catalogue (PI. Dist. I.). 



* 



| Jenaische Denkschr. VIII., p. 165. 



