44 James FRANCIS ABBOTT, 
a cup-shaped cavity just below the otolith sac. The presence of 
any circumperipheral canal is denied. He also described a remarkable 
structure in the neighborhood of the tentacles, — a cavity in which 
lie large and powerful longitudinal muscles and which opens to the 
exterior by a pore. He conceives this to be possibly excretory in 
function, and surmises that it may be homologous with the water- 
vascular system of Planarians. However, as WILLEY suggests, there 
is no doubt that Korornerr was describing a section through the 
tentacles, which he was unable to orient correctly. The muscular 
fibers of the tentacle stalk might well be mistaken for “longitudinal 
muscles”. 
3. Wittey’s Ctenoplana. 
No further discoveries of either Ctenoplana or Coeloplana were 
reported until Arraur Wizzey, in 1896, in the course of his in- 
vestigations in the South Seas, discovered 4 specimens of KOROTNEFF'S 
Ctenoplana, apparently belonging to different species, three of the 
specimens being greenish and one crimson. Wıruky was able to 
keep them under observation in the living state some time and 
established the fact that Ctenoplana swims through the water as a 
Ctenophore does, solely by the aid of its costae. The most important 
contribution that he was able to add to the morphology of the form 
was the discovery of the male gonads, which are described as being 
located “at the bases of the two end-lobes of the main portion of 
the gastro-vascular system” and hence apparently radially disposed 
in relation to the otolith. 
The most striking thing in Wizzey’'s description is that these 
gonads open to the exterior, dorsally, by one or more simple ducts 
the mouths of which he just below the level of the surmming 
plates. The cell proliferations which constitute the testis are 
developed upon the outer walls of the coeca from the gastric canals. 
The whole arrangement is strikingly at variance with anything we 
are familiar with in either Coelenterates or Platyhelminthes. WıILLEY 
asserts that the dorsal surface bears no cilia. He further states 
that the sensory tentacles near the apical sense organ, instead of 
forming a closed circle, as described by Korornerr in reality are 
arranged in two semicircular areas on either side of the otolith sac, 
— the circle being broken in the line of the tentacular plane. 
Wizzey’s figures are unsatisfactory inasmuch as he does not attempt 
