EE POET ON THE TUNICATA. 
277 
commences by coiling six or seven times around it (PL XXXYI. fig. 8, t.v.). Figure 7 
on Plate XXXVI. shows a section through the testis {t.v.) with some of the coils of 
the vas deferens {v.d.) on its surface. No ova and no embryos nor larvae were found 
in any of the Ascidiozooids examined. 
Leptoclinum speciosum var. asperum, nov. (PI. XXXIV. figs. 8-13, and PL XXXVI. 
fig. 9). 
The Colony is a thin incrusting layer of irregular shape, attached by its whole extent. 
The upper surface is somewhat uneven, and it is rough all over. The colour is white. 
The length is about 5 cm., the breadth about 3 cm., and the thickness from 
1 to 2 mm. 
The Ascidiozooids are numerous and fairly large. They are closely placed all over 
the surface of the colony. Some cloacal apertures are present here and there, but no 
definite systems are visible. The Ascidiozooids are elongated antero-posteriorly, and are 
placed vertically in the colony. The thorax and abdomen are distiuctly separated. 
The Test is hard and brittle. It is opaque white throughout. The matrix contains 
small test cells, numerous calcareous spicules, and, in the superficial layer, a few bladder 
cells. The spicules are stellate, of regular form, and of considerable size. Ectodermal 
prolongations from the Ascidiozooids are also met with in the test. 
The Mantle is moderately thick and muscular, the branchial sphincter is powerful, 
and retractor muscles are present. 
The Branchial Sac is small. There are four rows of short stigmata, and the trans- 
verse vessels between them are wide. 
The Endostyle is wide and conspicuous. It undulates greatly from side to side in its 
course. 
Th.e Dorsal Lamina is represented by a series of long narrow langiiets. 
The Tentacles are large. They are sixteen in number, and are of two sizes, placed 
alternately. 
The Alimentary Canal is large. It forms a long narrow loop behind the branchial sac. 
Localities. — (a.) Bahia, Brazil, September 1873 ; depth, 7 to 20 fathoms. 
(6.) Station 142, December 18, 1873 ; lat. 35° 4' S., long. 18° 37' E.; depth, 
150 fathoms ; bottom, green sand; bottom temperature 47° F. 
Several colonies obtained in shallow water off Bahia, on the east coast of South 
America, form a very distinct variety. In external appearance they differ markedly 
from the typical forms of the species, found in the same locality, in having the 
surface finely roughened all over in place of being smooth. As the internal structure 
also differs somewhat in the two forms, it is doubtful whether it might not be better to 
