from various other localities are probably referred to this species 

 -only because of thé insufficiency of Selenka's description. 



Polyplectana oculata n. sp. 



Taboga, Panama. XI. 1915. The shore, between corals. 69 specimens. 

 The specimens at hand are of very varying size, the largest 

 measuring ca. 15 cm in length and the smallest but 3 cm, but the 

 greater part of them measure 7 — 9 cm by 1 — 1,5 cm in diameter, 

 v The body-wall is very thin and soft and the specimens are so adhérant 



Fig. 12. Pieces of calcareous ring in Polyplectana oculata 1, 

 Polyplectana longogranula 2 and Polyplectana kefersteinii. 3X9. 



that it is exceedingly difficult to separate them. The colour is 

 dorsally dark grey and ventrally nearly white. The tentacles are 

 in some specimens clear yellow and in others more brownish. The 

 specimens have usually 25 tentacles, but the number is varying 

 from 18 — 27 and not closely correlated with size. Each tentacle 

 is in the distal two thirds of its length supplied with 9 — 10 pairs 

 of digits, which are united by a web. On the oral disk there are 

 very distinct eye-spots. 



The cartilaginous ring is well developed and encloses the 

 posterior margin of the calcareous ring. The calcareous ring (Fig. 

 12. 1) consists of 25 pieces, of which the radial ones are perforated 

 for the nerves and somewhat differing in shape from the others. 

 On the external side, there are distinct muscular impressions. 

 There are many polian vesicles and a single stone-canal. The 

 madreporite is elongated along the one side of the stone-canal. The 



10* 



