REPORT ON THE TUNICATA. 89 



The British Museum collection contains specimens of this species from "Philip Bay," 

 "Falkland Islands," " Antarctic Seas," " Off Dungeness," '' Mouth of Peckett Harbour," 

 and " Possession Bay." 



The Challenger specimens are all from the Straits of Magellan and the neighbourhood 

 of the Falkland Islands, as follows : — 



One specimen from Station 312, January 13, 1876; lat. 53° 38' S., long. 70° 56' 

 W. ; depth, 10-15 fathoms; bottom, mud. Eight specimens from Station 315, January 

 26, 27, 28, 1S76 ; lat. 51° 40' S., long, 57° 50' W. ; depth, 5-12 fathoms; bottom, sand 

 and gravel. One specimen from Station 316, February 3, 1876 ; lat. 51° 32' S., long. 

 58° 6' W. ; depth, 4-5 fathoms ; bottom, mud. 



Boltenia pachydermatina, Herdman (PI. VII. figs. 6-8). 



Bui tenia pachydermatina, Herdman, Prelim. Rep., Proc. Roy. Soc. Edin., 1880-81, p. 81. 



External Appearance. — The body is between ovate and fusiform in shape, and is 

 compressed laterally. The posterior (upper) end is bluntly pointed ; the anterior end is 

 narrow, becoming gradually continuous with the stalk ; the dorsal edge is more convex 

 than the ventral. The stalk is long, thick, twisted and creased, and rather tapering 

 downwards towards the point of attachment. The apertures are conspicuous but not 

 prominent, and not distant, being placed at the points of junction of the middle with 

 respectively the anterior and posterior thirds of the body. 



The surface of the body is smooth but deeply grooved longitudinally ; the stalk is 

 closely wrinkled transversely. 



The colour of the body is dull creamy white ; of the stalk, yellowish-brown. 



Length of the body, 10 cm. ; breadth, 5 cm. ; length of the stalk, about 20 cm. 



Tit e Test is very thick, tough, and stiff, between cartilaginous and coriaceous in 

 texture ; it is white and glistening on the inner surface. 



TJie Mantle is thin but muscular, and adheres slightly to the test. 



The Branchial Sac has about six folds on each side. The internal longitudinal bars are 

 numerous, about eight on the folds and six in the interspaces. The meshes are transversely 

 elongated, and contain each about nine stigmata ; they are always divided by a narrow bar. 



Tfie Tentacles are compound, and densely branched. They are sixteen in number, 

 and of two sizes, placed large and small alternately. One of the tentacles is much larger 

 than any of the others. 



Tlie Dorsal Tubercle is large, and circular in outline; the surface is marked with a close 

 and elaborate pattern. 



This large and striking species, although apparently common and well known, has, so 

 far as I can ascertain, never been described or named. There are some very good 

 specimens of it in the British Museum collection, labelled as follows : — New Zealand 

 (about six specimens), Van Diemen's Land (about six specimens), Godthaal, Danish 



