REPORT ON THE TUNICATA. 155 



Kerguelen Island, at Station 150; February 2, 1874; lat. 52° 4' S., long. 71° 22' E.; 

 depth, 150 fathoms; bottom temperature, 1°'8 C. ; bottom, rock. 



Styela gyrosa, Heller. 



(?) Cynthia rrmiru.ta, Philippi, Miiller's Arcbiv, 1843. 



Styela gyrosa, Keller, Uutersuch. ii. d. Tuiiioaten d. adriat. Mceres., Abth. 3, p. 15, 1877. 



This large and apparently widely distributed species was found by the Challenger 

 expedition at Port Jackson in considerable quantity. There are some large specimens of 

 it from the same locality in the Liverpool Free Public Museum. They were dredged 

 and brought home by Mr. Patterson. 



As Heller (loc. cit.) has lately given a long description of the Mediterranean specimens, 

 and as the Australian ones seem to correspond in all particulars, little remains to be 

 said here. The Challenger specimens are even more massed together into pseudo-colonies 

 than Heller's seem to have been, and occasionally half-a-dozen or more individuals are 

 found united by the fusion of their tests into a rounded clump, placed upon an irregularly 

 twisted peduncle, nine or ten centimetres in length. 



A number of specimens were dredged in 6 fathoms of water at Port Jackson, 

 Australia. 



Styela convexa, Herdman (PL XIX. figs. 3-4). 



Styela convexa, Herdman, Prelim. Eep., Proc. Roy. Soc. Edin., 1880-81, p. 69. 



External Appearance. — The body is rudely hemispherical, or bluntly conical in shape, 

 and is not flattened laterally. The anterior end and the sides are convex ; the posterior 

 end is large, and is attached to a stone, and slightly expanded at the edge. The branchial 

 aperture is terminal, and is placed rather to the ventral side of the middle of the anterior 

 end, but forms its most prominent point; the atrial aperture is moderately distant, at 

 the dorsal edge of the anterior end; both are sessile and inconspicuous. 



The surface is moderately smooth, and is finely creased in all directions, especially 

 round the apertures. The colour is a dull yellowish-brown, but lighter on the margins of 

 the posterior end. 



Length of the body, 2 cm.; breadth of the body (dorso-ventral), 2*6 cm. 



The Test is thin, but very tough; it is white on section. 



The Mantle is closely united to the test, and has the musculature fine but close. 



The Branchial Sac has four folds upon each side. There are aboul eighl internal 

 longitudinal bars upon a fold, and the same number in the interspaces. The meshes 

 are elongated antero-posteriorly ; each contains about three stigmata, and is divided 

 transversely by a narrow horizontal membrane. 



The Dorsal Lamina is slightly crimped but plain; the edge is even. 



(ZOOL. CHALL. EXP. — PART XVII. 1882.) K 21 



