PRELIMINARY NOTES ON GOJCLOPL.VXA. 



105 



the larger species will frequently measure 5 or 6 em. in longest diameter; 

 the same animal contracted, shrinking to one centimeter across. It 

 .seems to adapt itself to its surroundings in color, and heavily pigmented 

 individuals as well as nearly transparent ones will be found in appro- 

 priate surroundings. 



It is very sluggish and apparently inhabits a very limited field. 

 The ventral surface is heavily ciliated, the dorsal not at all. The ventral 

 surface is flat, and it never doubles upon itself as described for Gtenoplana. 

 When dropped into the water the edges curl in, all around, and it falls 

 through the water in a shapeless lump. 



It floats on the surface of the water with ease, and at such times 

 moves along the surface, snail fashion, on a film of slime. This frequent- 

 ly extends beyond the periphery so that it is possible to push the animal 

 all about the jar with a needle, without coming within a centimeter of 

 touching the edge of the bod}'. I have never seen it floating except in 

 captivity and it tenaciously resists being taken from the rock on 

 which it is found. 



Where one is found, others are quite sure to be, and the situations 

 in which they are found are sometimes strongly suggestive of 

 multiplication by division, tho no evidence has been obtained yet as to 

 that point. 



It would be as misleading as it would be useless to speak of front or 

 back or sides in connection with this animal, at least as regards locomo- 

 tion. It not only crawls in any direction whatever but it frequently 

 goes in more than one direction at once and the two halves, starting off 

 for opposite sides of the dish, often stretch the middle part to the break 

 ing point. At other times, it turns and twists upon itself until, tho 

 the outline may be fairly regular, the turns and coils of the internal 

 organs show that the interior is much confused. 



When floating C. mitsuJcurii frequently drops down its long 

 tentacles which wave about in the water in very graceful fashion (fig. ]). 



The dorsal surface is ordinarily heavily pigmented, the pigment 

 being contained in large cells. Where the animal contracts, these cells 



