48 
THE VOYAGE OE H.M.S. CHALLENGER. 
a very short course, ends not far in front of the oesophageal aperture. The anus has 
a slightly thickened band on the margin, hut is not lobed or fringed in any way. In 
some specimens the intestine is wider than is shown in the figure (PI. III. fig. 14), and is 
then evidently dilated by its contents. 
Botrylloides perspicuum, var. ruhicundum, nov. (PI. I. figs. 6, 7 ; PI. III. figs. 15-18). 
The Colony is small, rounded or ovate, slightly lobed and moderately thick. The 
surface is somewhat uneven, but smooth. The general colour is a light reddish-purple in 
the centre, and white or grey round the edge. The anterior ends of the Ascidiozooids are 
slightly lighter. The common cloacal apertures are inconspicuous. 
The length is 1‘5 cm., the breadth 1 cm., and the average thickness about 3 mm. 
The Ascidiozooids are elongated antero-posteriorly and placed at right angles to the 
surface of the colony. Each is about 2 mm. in length and about 0’7 mm. in greatest 
breadth. The anterior end is about 0'5 mm. in diameter. 
The Test is firm, but- soft. At the margins of the colony it is nearly transparent and 
usually of a light grey colour. In some places it is almost white. Elsewhere it is 
coloured by the Ascidiozooids. The terminal knobs of the vessels are in some places 
yellow and conspicuous. In other parts they are of a greyish colour like the test or 
slightly more opaque. The matrix of the test is homogeneous and very transparent in 
sections. The test cells are very minute and inconspicuous ; vessels are numerous and 
branch freely, especially near the surface and edges of the colony. The terminal knobs are 
large and more or less globular or ovate in form. They contain many corpuscles, some of 
which are coloured with a pale yellow pigment. 
The Mantle is extremely thin and delicate. 
The Branchial Sac is large. The transverse vessels are all of the same width. There 
are three internal longitudinal bars on each side. The stigmata are regularly placed, 
there are two or three in each mesh. 
The Dorsal Lamina is a plain membrane. 
The Tentacles are eight in number, four long and four short, placed alternately. 
The Dorsal Tubercle is a small ovate aperture with prominent edges placed in the 
middle of the dorsal part of the prebranchial zone. 
Locality. — Station 212, January 30, 1875; lat. 6° 54' N., long. 122° 18' E. ; depth, 
10 fathoms; bottom, sand. 
The above description refers to half a dozen small colonies growing over lumps of 
sand, Annelid tubes, shell fragments, &c., dredged near the Philippine Islands, from a 
depth of 10 fathoms. 
Several of the colonies are about the size given above ; the smallest is 5 mm. in length 
and 3 mm. in breadth. 
