EEPOHT ON THE TUNICA TA. 
845 
and form a slight projection towards the peribranchial cavity (PI. XLVI. fig. 12). As 
the number of ova and their size increases the projection becomes larger and the ova 
pass completely into it, thus forming a young polycarp, attached to the mantle by its 
base. Endocarps are also present on the inner surface of the mantle. They have 
the usual irregular form and soft grey appearance (PI. XLYI. fig. 14, en.c.). 
Tailed larvae of large size are present in abundance in the peribranchial cavities of 
some of the Ascidiozooids. They have short ovate bodies and very large tails (PI. XLVI. 
fig. 11). Adhering papillse are present at the anterior end of the body, and the single 
pigmented sense-organ is situated nearer to the anterior' than to the posterior end. 
The tail is provided with a wide membranous margin (PI. XLYI. fig. 11), which is 
supported by transversely running rays or fibres exactly like those described by Giard ^ 
as being present in the larva of his Polystyela lemirri. 
In external appearance this species shows a certain resemblance to aggregations of 
Styela grossularia and some other allied Simple Ascidians such as are formed where 
individuals are closelv crowded too;ether and become attached to their neioiibours’ tests. 
The presence, however, of the thin spreading test margin at the edges of the colony, and 
of the numerous vessels with their dilated bulbs, shows that this is a colony and not 
merely an aggregation of individuals. The manner in which the young Ascidiozooids are 
imbedded in the test is also very different from the condition found in Styela grossu- 
laria, where, wLen aggregations take place, the young Ascidiozooids are merely slightly 
attached to the surface of the tes’t of the older individuals, and only become firmly and 
closely united with them as they grow older and the test increases in amount. 
The specimen from Samboangan may possibly prove, when more specimens are 
examined, to be a distinct variety. It is a small colony incrusting a fragment of an Alga, 
and is rather darker in colour than the specimens from the Strait of Magellan, and the 
Ascidiozooids seem to be of smaller size. The only difference I have detected in the 
internal structure is in the branchial sac, where, in the Samboangan specimen, there are 
no delicate transverse vessels crossing; the meshes. 
O 
Cliorizocormus,^ u. gen. 
Colony consisting of a number of distinct masses of small size united by irregular 
branched stolons. 
Ascidiozooids placed either singly or in small groups in the test. When more 
than one is present they do not project above the general level. The body is 
not divided into thorax and abdomen. 
T'est relatively small in amount, slightly incrusted with sand. Test cells few, and 
bladder cells absent. Yessels present in the test and stolons. 
1 Assoc, f rang., t. iii., 1874. 2 and xo^fio;. 
(ZOOL. CHALL. EXP. — PART XXXVIII. 1886.) 
Pp 44 
