394 
KJERSCHOW AGERSBORG 
ther. Ail the tentacles were withdràwn most the time, but 
the dorsal pair cornes out first; then the labial pairs. Inside, 
the mouth is also supplied with a closely serrated (hooked) 
prehensile organ one on each side and caudad to the labial 
tentacles. On the posterior part of the head i^ a pair of 
small dépréssions, with a very small tubercle in each. 
Fins:—The fins are oval, about as long as the width of 
the trunk, but not so wide. The caudal border, angular, 
sometimes notched on the proximal side. The caudal border 
is fringed with fine cirrhi, one third the distance from the apex 
and nearly to the base. The arrangement of the muscle 
fibres in the fins gives a diamond efîect; the fibres which pass 
from the base to the periphery are in constant wave-like 
motion. The fins are located in large grooves at the antero- 
ventral part of the trunk which is here narrowed into a 
distinct but short neck. On the ventral part of the neck and 
between the fins is the remaining part of the foot which con- 
sists of two arched lobes that meet with their base in the mid- 
ventral line and arch outward. The proximal borders of 
these lobes do not meet altogether in the mid-ventral line 
but corne apart in about the middle foiming an oval déprés¬ 
sion. At the caudal border, in the mid-ventral région, is a 
smaller médial lobe which is partly covered by the other pedal 
lobes just mentioned. 
Body:—The pellucid trunk of the body tapers posteriorly 
into a rather fine point; the trunk is annulated with from 
four to six muscle bands; a latéral groove on each side divides 
the trunk into a large arched dorsal portion about one third 
larger than the ventral part which is straight. The posterior 
sixth of the body, may or may not be red; this is grooved off 
from the rest by a ciliated groove. This ciliated groove is a 
characteristic feature of the species. It is not always pos¬ 
sible to see the vibrations of the cilia, for, indeed, they may 
be at times in an inactive state making it practically impos¬ 
sible to see their vibrations, if they vibrâte at ail during such 
times. That is, in the same individual, the cilia of the 
caudo-ciliated groove are not always vibrating, and then, 
they may not be seen; while at other times they can be seen 
