allied to Rhabdopleura. 345 
fibres passing from the oral region backward to the pedicle. 
The same hypodermic layer covers the latter, which is like- 
wise ringed all round by rather regular transverse furrows, 
the coat, moreover, being thicker dorsally than ventrally. 
Within the foregoing is a thick elastic coat continuous with 
that on the body, and which in a line with the narrow (ven- 
tral) margin is bent inward at a sharp angle, so as to form a 
longitudinal ridge along the pedicle. Internally are numerous 
bundles of longitudinal muscular fibres, which are especially 
dense on each side of the ridge. In longitudinal sections 
these fibres form large coarse fasciculi; and their origin is 
as in Rhabdopleura, viz. near the oral region. In trans- 
verse sections the centre of the pedicle is occupied by a little 
connective tissue and granules, and there does not seem 
to be evidence of a distinct canal. At the tip, however, in 
longitudinal sections a central cavity is sometimes seen—con- 
taining cells and granules, and which may be homologous 
with the peduncular gland of Loxosoma. The buds arise 
from the latter region, often from the ventral aspect. It is 
interesting that Prof. Allman found at the end of the funiculus 
of Lhabdopleura a somewhat reniform dark-brown body, 
which he considered a statoblast. The spot from which the 
buds arise in Cephalodiscus is likewise towards the tip. No 
trace of a nervous system was observed. 
In most of the specimens a pair of large rounded whitish 
masses conspicuously distend the body-wall anteriorly under 
the eyes; and, indeed, one or other of the latter generally 
clings to the undeveloped ova adjoining it. In transverse 
section through the ovary one of the ova is found to be con- 
siderably larger than the other, often twice the size; and thus 
the outline of the body is asymmetrical. Hach shows germinal 
vesicle and spot, and is surrounded by a transparent invest- 
ment. Moreover each has developing ova of various sizes 
abutting on it ventrally; and since the extension of the 
large ova is mainly external, the smaller ova and their 
clear globules are compressed towards the middle of the body 
as well as ventrally. A fine membrane (ovisac ?) appears to 
surround the large and the small ova in common, while each 
of the latter has its own hyaline investment. On extrusion 
(whether by anus, mouth, or otherwise is yet unknown) the 
large and somewhat pyriform ovum is provided with a well- 
formed pedicle of the transparent investment—truncated at the 
extremity for attachment. An ovum is occasionally found 
amongst the tentacular plumes, as in Phoronis, with its 
swarms of minute eggs ; but such is probably accidental. The 
ova are filled with the usual granular contents, and each is 
