NUDIBRANCHIATA OF THE L.M.B.C. DISTRICT. 143 
scattered over the tips of the dorsal and oral tentacles. 
The eyes are very distinct, and are placed some way behind 
the bases of the dorsal tentacles. Sections however show 
that they are sessile upon the cerebral ganglia. 
The cnidophorous sac is pyriform in outline, the upper 
end being pointed while the lower wider end communicates | 
with the apex of the hepatic cecum by a short straight 
tube (Pl. VIII. fig. 7). The wall of the cnidophorous sac 
is unusually muscular, and while one of the animals was 
under observation in the living condition we saw a large 
number of the cnida expelled with force from the terminal 
opening (Pl. VIII. fig. 8.) in the exploded or evaginated 
condition. The cnida are large (measuring 0°028 mm. in 
length and 0:01 mm. in breadth) and are of an ellipsoidal 
shape (Pl. VIII. fig. 9).* The thread is distinctly seen to 
be coiled along the axis of the cell and not transversely 
to it as in Facelina drummondi and other species. When 
evaginated the thread is seen to be provided with num- 
erous long sharp spines placed alternately so as to give 
rise to a zig-zag appearance (Pl. VIII. fig. 9). 
Galvina picta, Ald. and Hance. 
We collected half a dozen specimens of this species at 
Hilbre on September 9th, 1889, and several on March 21st, 
1890; and Mr. A. O. Walker dredged a specimen in 
Colwyn Bay in February, 1890. It appears to be becom- 
ing more common in the district. 
Figure 11 on Plate IX. shows a transverse section 
through the tip of one of the cerata of this species. On 
the inner side of the large ectoderm cells 1s found a thin 
layer of connective tissue (mes.), then an irregular series 
of blood sinuses, then another thin layer of connective 
tissue, and then, occupying the centre of the section, is 
* Described by Vayssiere as renifcrm (loc. cit., p. 78.) 
