REPORT ON THE TUNICATA. 209 



way inside the atrial aperture. In almost its entire course the alimentary canal is concealed 

 by the genital and renal glands. A system of fine tubules, branching dichotomously, 

 slightly swollen at the points of division, and ending in elongated enlargements, is 

 present upon the wall of part of the stomach and intestine. The heart lies along the 

 ventral edge of the stomach. The faeces in the rectum are of a dark greenish -brown 

 colour. 



The ovary ramifies over the anterior part of the intestine and in the narrow 

 intestinal loop, and the oviduct is seen distinctly running from the groove between the 

 stomach and intestine, along the lower edge of the latter, to end near the anus, beyond 

 which it projects slightly. The testis is composed of numerous small oval or pyriform 

 vesicles of a pale yellow colour, connected with the terminal twigs of a duct which 

 branches dichotomously over the intestine. The vas deferens runs alongside the oviduct 

 as a conspicuous pale yellow tube. The oviduct is very delicate, and lies behind the vas 

 deferens, partly encircling it. 



The renal gland is of great extent, covering almost the entire stomach and intestine. 

 It consists of a number of vesicles of large size, having in mass a pale brown colour. 

 Each vesicle is in its outer part perfectly transparent, but it encloses in its centre one 

 or more rather brilliant yellowish-brown concretions, which are soluble in hydrochloric 

 acid, and have a concentrically laminated structure, and often a dark brown centre. 

 Besides these brown concretions, there are also usually present in each vesicle several clear 

 rosette-shaped bunches of crystals, which may possibly not be urinary deposits, but may 

 have been formed by post-mortem changes. The vesicles are quite isolated, and com- 

 municate with no duct. 



There are also to be seen scattered through the renal mass a number of small spherical 

 opaque white bodies, apparently lying quite freely in the surrounding tissues. These 

 dissolve with effervescence in hydrochloric acid, revealing a brown centre similar to the 

 concretions mentioned above. This centre also rapidly dissolves, leaving a dark brown 

 nucleus, which very slowly dissolves, breaking up into a brown del iris which remains 

 undissolved. These white bodies are probably the ultimate form of the brown concretions 

 seen in the vesicles. 



Several specimens of this species were obtained off the coast of Buenos Ayres, South 

 America, at Station 320; February 14, 1876 ; lat. 37° 17' S., long. 53° 52' W.; depth. 

 GOO fathoms ; bottom temperature, 2°'7 C; bottom, hard ground; and two specimens in 

 the Straits of Magellan, at Station 313 ; January 20, 1876 ; lat. 52° 20' S., long. 68° 0' AY 

 depth, 55 fathoms ; bottom temperature, 8°'8 C; bottom, sand. 



