REPORT ON THE TUNICATA. 205 



The viscera are large ; the intestinal loop is narrow, and extends for a considerable 

 distance anteriorly. 



Specimens of this species were obtained at three localities off Kerguelen Island, Station 

 149, namely, Balfour Bay, January 19, 1874, 20 to GO fathoms, 5 specimens ; Royal Sound, 

 January 20, 1874, 28 fathoms, G specimens ; and Kerguelen, 10 to 60 fathoms, 2 specimens. 



Ascidia vasculosa, Herdman. 



Ascidia vasculosa, Herdman, Prelim. Rep., Proc. Roy. Soc. EJin., 1879-80, p. 465. 



External Appearance. — The shape is very irregular, and is somewhat quadrangular 

 and depressed. The anterior end is a little prolonged and narrower than the rest, and 

 the body is attached by the left side near the base. The branchial aperture is not quite 

 terminal, being on the right side of the anterior extremity. The atrial aperture is also on 

 the right side, nearer the dorsal than the ventral edge, and a little in front of the middle. 

 Both the apertures are rather depressed and concealed. 



The surface is very irregular, it is grooved and mammillated, and has Compound 

 Ascidians, Annelid-tubes, &c, adhering to it. It is of a light yellowish-grey colour, is not 

 opaque, being rather hyaline at the edges, and showing everywhere numerous blood-vessels 

 ramifying near the surface. The terminal twigs of the vessels, with their swollen ends, 

 are a prominent feature. 



Length of the body, 9 cm.; breadth of the body, 5"G cm. 



The Test is cartilaginous and solid, and varies in thickness from less than 0"5 mm. on 

 the right side behind the middle to l - 5 cm. on the left side near the place of attachment. 

 The apertures are lobed indistinctly ; the vascular trunks enter on the left side near the 

 ventral edge, and branch usually cbchotomously, the terminal twigs ending in swollen 

 knobs. The test shows no bladder cells. It contains the usual small spherical fusiform 

 and stellate cells, and many minute granides. Crystals or concretions are also present, 

 generally in the form of short rods and crosses. 



This is a specimen from the collection made at Kerguelen Island, of which nothing 

 remains but the test. This organ seemed to me, however, to be so distinct from that of 

 the other known species of Ascidia, that I described it in the first part of the Preliminary 

 Report under the name of Ascidia vasculosa. 



The shape is very irregular, having various grooves and projections, and being covered 

 with several adhering animals. The blood-vessels are the distinctive feature. They are 

 numerous and of large size, and show very distinctly from the outer surface of the test. 

 Probably the crystals mentioned in the above description are a post-mortem change, 

 possibly the result of the long immersion in spirit. 



One specimen (the test only) was found at Station 149, Royal Sound, Kerguelen 

 Island, January 20, 1874 ; depth, 28 fathoms. 



