164 ARTHUR WILLEY. 
nounced in the neighbourhood of the apertures, while the lips 
of the latter are a pure dark red, interrupted by four light streaks 
which indicate the quadripartite character both of the buccal 
and atrial orifices. 
As seen in the figures, the individuals are not always attached 
to the rock by the same side, but sometimes by the ventral 
side, sometimes by the right, and sometimes again by the left 
side (Fig. 12). 
The total length of the group represented in Fig. 12 was 
91°5 mm., and the greatest breadth of the group 31 mm. 
The animal of which an outline is given in Fig. 13 measured 
51°5 mm. in length, and the atrial opening was 20°5 mm. 
removed from the buccal aperture. By its external appearance 
alone it is an extremely well-marked species. The surface of 
the coriaceous test is in some places wrinkled and in other 
places smooth. 
The most remarkable peculiarity of the new species, how- 
ever, is the faculty which it possesses of evisceration. 
After I had had them for a short time in a vessel where 
everything was fresh and in good condition, I suddenly dis- 
covered a number of digestive tracts lying at the bottom. On 
then inspecting the Ascidians, of which there were several 
species present at the time, I found that they were all living 
and in a bealthy condition. 
Eventually I actually observed the process of evisceration 
taking place (cf. large individual to the right in Fig. 12). It 
takes a rather long time before the process is completed. Itis 
effected by violent periodic contractions of the atrial siphon. 
After it is over the animal presents a perfectly normal and 
healthy appearance, opens and closes its siphons, and is suscep- 
tible to irritation and to the influence of cocaine. So constant 
is this ejection of the digestive tract that if it is desired to pre- 
serve specimens intact, they must be placed in alcohol imme- 
diately after capture. 
The dissection of an individual which has ejected its bran- 
chial sac and intestine discovers no laceration whatever; and 
undoubtedly, in ignorance of the habit of evisceration, one 
