180 THE* VOYAGE OF H.M.S. CHALLENGER. 



over the inner white surface of the test, and they are merely cavities in connection 

 with the Mood- vessels, which may also be seen here and there in sections. A number 

 of smaller blood cavities are present just below the outer surface of the test, recalling the 

 arrangement in Ouleolus, but the larger vesicles are always more deeply placed 

 (PL XXIII. fig. 13). 



The folds in the branchial sac are narrow, and the internal longitudinal liars are 

 slender. The. arrangement of the transverse vessels is shown on figure 11, Plate 

 XXIII. ; above the large transverse vessel (tr.) two rows of stigmata are seen passing 

 into one. In some parts of the sac the stigmata are longer and narrower than in the 

 part figured. On account of the fewness of the internal longitudinal bars, the meshes 

 are much elongated transversely. Muscle fibres are seen well in some of the vessels 

 of this branchial sac (PI. XXIII. fig. 12). 



Three specimens of Pohjcarpa sulcata were dredged off Banda, in the Moluccas ; 

 depth, 17 fathoms. 



Pohjcarpa pedata, Herdman (PL XXIV. figs. 1 and 2). 



Pohjcarpa pedata, Hordman, Prelim. Rep., Proc. Roy. Soc. Edin., 1880-81, p. 71. 



External Appearance. — This species is irregularly club-shaped, and consists of a 

 long stalk supporting a somewhat globular body produced anteriorly. The posterior end 

 of the body is broad and rounded, and passes rapidly into the narrow stalk, which is 

 nearly as long as the body. The ventral edge is nearly straight ; the dorsal is strongly 

 convex in its posterior half, and straight in the anterior part, The animal is attached 1 iy 

 the extremity of the long narrow stalk. The branchial aperture is terminal, it is very 

 prominent, and is directed anteriorly ; the atrial is on the dorsal edge, about half way 

 down the body; it projects, and is directed anteriorly and dorsally; both are distinctly 

 four-cleft. 



The surface is smooth, but grooved and creased somewhat. The colour is yellowish- 

 white, with a tinge of red on the stalk. 



Length of the body (total), 10"5 cm.; breadth of the body, 4 cm. 



The Test is thin but tough. 



The Mantle is moderately thick, but adheres here and there to the test ; the musculature 

 is close but not strong. 



TJw Branchial Sac has four folds upon each side. The transverse vessels are all of one 

 size. The internal longitudinal bars are numerous. The meshes are slightly elongated 

 transversely, and contain each five or six stigmata, 



TJie Dorsal Lamina is a plain membrane. 



The Tentacles are long and of a la-own colour. There are twenty -five of them, and 

 they are all of one length. 



