4 BRITISH TUNICATA. 



which it stretches in contact with the branchial sac, 

 and on reaching the atrium it opens into it. In its 

 course the intestine forms two wide loops. The rectal 

 portion is long and the anal orifice is large, and has 

 the margin reflected and reticulated, as is the case in 

 Pelonaia. 



The stomach and intestine have not a coating of 

 vesicular matter like that observed in Asculia, but a 

 rudimentary hepatic organ can be observed. 



The arrangement of the reproductive organs is 

 rather peculiar. The ovary is a dense, elongated 

 mass, lying against the right side of the stomach in 

 the first loop of the intestine. It is infolded in a deli- 

 cate transparent membrane which seems to be a dupli- 

 cature of the lining membrane. This membrane also 

 appears to be reflected over the alimentary tube and 

 to fix it in its position like a peritoneum. The oviduct 

 passes from the attenuated extremity of the ovary, 

 proceeds towards the dorsal margin, runs upwards 

 adherent to the intestine, and, ultimately becoming 

 attached to the wall of the branchial sac, opens into 

 the atrium a considerable way in advance of the anus. 

 There is a small bulbous enlargement at the termina- 

 tion of the tube. The male secreting vesicles are very 

 minute ; they coat the lower portion of the intestine 

 and the pyloric extremity of the stomach. The vas 

 deferens is a delicate tube, which, passing between the 

 stomach and the ovary, follows the oviduct to its termi- 

 nation, and there opens like it into the cloaca. 



[Considerable difficulty has been experienced in work- 

 ing out the synonymy of the three species of Giant i 

 described in this volume, and the references given 

 may not all be correct. Some of the earlier descrip- 

 tions are too meagre and the illustrations too inaccurate 

 to definitely assign them to any one species, and in 

 some cases the species intended to be represented by 

 an author can only be inferred from the synonymy 

 or references quoted by him. 



The following, copied verbatim, is the synonymy 



