38 H. N. MOSELEY. 



pletely flattened. The posterior extremity narrowed to a 

 blunt point. Tentacles were absent. 



In the centre of the anterior extremity was a slight depres- 

 sion or pit, apparently an organ of sense, and which seemed 

 to be used by the animal as such. 



The mouth is elongate and folded, and large in proportion 

 to the size of the body, as usual in young planarians. The 

 ramifications of the digestive tube were already marked out, 

 though not very distinctly. The forward prolongation of 

 the main digestive tube passes as usual over the nervous 

 ganglia. 



The eyes were disposed in two irregular semicircles situate 

 one on either side of the ganglia, with their convex side 

 towards the latter. In one specimen there were twelve eye- 

 spots on one side and eleven on the other ; in the other eight 

 on each side. A posterior group of three eyes on either 

 side was in both of the specimens, separated from the 

 remainder by the passage between it and them of the last 

 branch given off by the main digestive tube before it passes 

 over the ganglia. These groups of eyes seem to be homo- 

 logous with those situate at the bases of the tentacles of 

 Stylochus pelagicus. 



The most interesting point about the present form is that 

 the eyes appear to have definite directions which correspond 

 exactly on the two sides of the body (see Plate III, fig. 13). 

 In the above described posterior group of eyes this condition 

 was especially marked, and was seen in both specimen^ of the 

 animal. Here the most posterior eye looks directly forwards, 

 the one directly anterior to it directly inwards, and the 

 outer one of the group obliquely inwards and backwards ; 

 five of the remaining eyes look directly upwards ; the others 

 have definite directions, as may be seen in the figure. The 

 arrangement of the most anterior eyes was not quite sym- 

 metrical. In the second specimen of the animal with but 

 eight eyes on either side, the posterior group had nearly the 

 same directions as in that just described. All of them 

 showed direction towards definite points. 



The specimen with twelve eyes on either side was of a 

 uniform pale whitish colour. The other specimen had its 

 upper surface covered with scattered, round, small, brownish 

 pigment spots. 



I3oth specimens were very lively, swimming by undulation 

 of the body margin. 



This planarian, from the seas of the East Indian Archi- 

 pelago, being devoid of tentacles, seems to indicate another 

 new pelagic species, which possibly should be referred to 



