EEPOUT ON THE TUNICATA. 
24 ^ 
Nine colonies, some of them fragmentary, of this species were obtained off the 
Cape of Good Hope, at a depth of 150 fathoms. Some of them are rather irregular in 
form and they are all iucrusted with sand (PI. XXXI. fig. 5). The colour, which is due 
mainly to the sand grains in the test, is light grey mth a distinct greenish tint. Some 
of the colonies have more imbedded and incrusting sand than others, the result being 
that they are harder and rather darker and show no traces of Ascidiozooids. In 
all cases the colony is quite opaque. 
Where they are visible the Ascidiozooids show as circular, less opaque, areas rather 
less than 1 mm. in diameter. They are closely placed, and occupy the whole outer 
surface of the colony with the exception of the lower end where it is attached. 
The test is occupied in all parts by the imbedded sand grains, Foraminifera shells, 
Sponge spicules, and other foreign bodies, so that very little of the test substance can 
be seen in sections (see PI. XXXI. fig. 9). In some places the granular test cells are 
very abundant. 
The mantle is transparent in all parts of the body, and the musculature is as strong- 
on the abdomen and post-abdomen as on the thorax. The branchial siphon is long 
(PI. XXXI. fig. 7), and the aperture is distinctly six-lobed. The sphincter muscle is 
weU developed. The atrial aperture is provided with a very large atrial languet 
(PI. XXXI. fig. 7). 
The stigmata of the branchial sac are remarkably long (see PL XXXI. fig. 6, sg.) 
and resemble those of Colella jpedunculata amongst the Distomidse. The dorsal languets 
are very short (PI. XXXI. fig. 8) ; and the endostyle though wide is not conspicuous. 
The oesophagus runs straight backwards and opens into the small narrow stomach, 
the waU of which is folded longitudinally. The intestine is nearly as wide as the 
stomach. It runs posteriorly for a considerable distance after leaving the stomach, and 
then turns abruptly to the dorsal edge and anteriorly to become the rectum. The 
loop thus formed is exceedingly narrow. The rectum is large and thin-walled. 
The post-abdomen is in some Ascidiozooids almost absent, while in others it is a 
long and narrow region of the body (PI. XXXI. fig. 10). The ova (o.) occur about 
the middle of its length, while the small ovate spermatic vesicles are placed more 
posteriorly (PI. XXXI. fig. 10, t.v.) The vas deferens {v.d.) is large and conspicuous. 
Psammaplidium exiguum, n. sp. (PL XXXI. figs. 11-12). 
The Colony is in the form of one or more short cylindrical projections from a 
common irregular incrusting base. The upper end is more or less rounded. The surface 
is sandy and rough. The colour is dark grey. 
The length, excluding the common base, is 6 mm., the breadth 4 mm., and the 
thickness 3 mm. 
