EEPOET OX THE THNICATA. 
289 
The spicules are abundant, especially in the upper layers of the test between the 
Ascidiozooids. They are usually stellate, with tapering rays and sharp points, but here 
and there deformed and irregular forms occur. They are most of them slightly larger 
than those of the named specimen of Leptoclimun albidum in which I examined 
the spicules, but are exactly like those of the named Leptoclinum albidum, var. 
luteolum. 
A small colony of roughly circular form and about 2 cm. across, which was obtained 
off San lago. Cape Yerde Islands, from a depth of 10 to 20 fathoms, seems also to belong 
to Leptoclinum albidum, Yerrill. It is attached to some object in the form of a 
dome about I’o cm. high, which it closely incrusts. The colony is slightly thicker, 
and the test seems a little whiter and more opaque than in the case of the specimen 
from deeper water in the same neighbourhood, but in other respects the structure 
is the same. 
One large colony and a few smaller ones and some fragments which were obtained in 
Simon’s Bay, Cape of Good Hope, from a depth of 10 to 20 fathoms, differ very slightly 
from those above described. They are of very irregular shape, and are thicker (from 1 to 
3 mm.) than the specimens from Cape Yerde Islands. They are also more opaque and 
not so grey in colour. The markings on the upper surface caused by the anterior ends 
of the Ascidiozooids are in some places rather smaller and more irregular, but in other 
parts of the colony they are of the normal size. 
The spicules both in shape and arrangement differ somewhat from those of both the 
North American and the Cape Yerde Island specimens ; they are rather larger, and are 
decidedly more irregular both in shape and distribution. Some of them are of a regular 
stellate form, but spherical, mammillated, and quite irregular spicules are of common 
occurrence throughout the test. Some of the larger irregular spicules are composed of 
several fan-shaped pieces joined together to form an incomplete disk which is marked 
by concentric and radial lines exactly like those on the discoid spicules of Cystodytes. 
This peculiar form of spicule occurs also in Leptoclinum subjlavum (see p. 294, and 
PI. XXXYIII. fig. 16). 
In the specimens from Simon’s Bay, as in those from the Cape Yerde Islands, the 
Ascidiozooids are distributed more or less evenly over the surface, and show no arrange- 
ment into systems or lines ; but in those colonies allied to Leptoclinum albidum which 
still remain to be considered, the anterior ends of the Ascidiozooids form on the upper 
surface a well marked reticulum composed of branching and anastomosing lines. This 
arrangement seems also to be generally found in Yerrill’s Leptoclinum albidum, var. 
luteolum, though not so markedly in the species itself. As all the specimens I have 
examined have been preserved in alcohol, unfortunately colour cannot be made use of as a 
distinguishing character. 
(ZOOL, CHAI/L. EXP. — PART XXXVIII.— 1886.) 
Pp 37 
