824 ARTHUR WILLEY. 
organisms, including young green-tinted Polychetes, young 
Planaria, Anthozoan larve, young Cirripedes in the Cypris 
stage, and four specimens of Ctenoplana. Three of the last 
were of a pronounced green colour, and the fourth was 
crimson. 
The green Ctenoplana, both on account of its colour and its 
shape, is an entirely new kind, and I shall name it C. Korot- 
neffi, The crimson variety may or may not be specifically 
identical with C. Kowalevskii; but as my sketches of the 
external form differ somewhat from Korotneff’s figures, I think 
it will be well to give it a provisional name with the object of 
engaging the attention of any zoologists who may have future 
opportunities for studying the genus. I propose, therefore, to 
call my crimson specimen C. rosacea. 
As TI had no chance of getting ashore, I had to make the 
best of the limited accommodation supplied by a small cutter, 
in order to observe the appearances presented by the living 
animals and their movements. Although I omitted to make 
accurate measurements of the living expanded animals, their 
average diameter would correspond closely in length with that 
of C. Kowalevskii, which, as stated by Korotneff, mea- 
sured 6 mm. 
Many of the external features of Ctenoplana were correctly 
described and figured by Korotneff, but his specimen appears 
to have been not very active; and although, as he says, he had 
it under observation in the living condition for three to four 
hours, it did not once extrude its tentacles, so that he only 
became aware of their existence in section. The consequence 
of this was that Korotneff was completely wrong in localising 
the plane of the tentacles. He placed them in the plane at 
right angles to that in which they actually occur. 
At the ends of one of the principal diameters of the disc- 
shaped body of Ctenoplana the margin of the body is incurved. 
Korotneff, without the smallest hesitation, describes these 
marginal bays as anterior and posterior in position, while, 
according to him, the tentacles were situated along the diameter 
at right angles to the “‘ antero-posterior ”’ diameter—that is to 
