91 



larvae, where it is always fouiul in a hori/.oiilal position ; but the fact that 

 there is a piece exactly corresponding to it on the ventral side makes the 

 homology more doubllul. The question must remain unsettled for Ihe 

 present. 



Species f (PI. XIII, Figs. 3 — 4, Texttigure 3(j). One s|)ecimen was 

 taken oil Minicoy (JMaldive Islands; 73° E, 7 X.; 26/ IV. 19U0), another in 

 the Bay of Bengal (89 E. 6" X.; 5/1. 1911). Both specimens are in begin- 

 ing metamorphosis; in both of them the postoral arms are broken, so that 

 their length cannot be ascertained; the remaining piece of one of them is 



Fig. 36. Skeleton of Echinopluleus transuersus, species f. Seeii from tlie dorsal side. 



Letters as in Fig. 34. 



%■ 



6 mm long. There is evidently no reason to doubt that they will prove to be 

 of about the same length as in species e. The two species are so very closely 

 alike that it is hardly possible from the scanty material available of the 

 species from the Indian Ocean to point out specific difTerences. That 

 they are, however, really difTerent species is evident from the fact that 

 there are no species of regular Echinoids known to occur both in the West 

 Indian Sea and the Indian Ocean. To enter on a detailed description of 

 the present species seems entirely unnecessary; reference to the figures 

 must be sufficient. 



The interesting problem to wiiich Echiuoiils tlieso remarkable larvce 

 must be referred now needs some discussion. As mentioned above I came 

 to the result, when describing the first of these larva\ the species e, that 

 it was probably the larva of Echinomdra liiciinlcr. The fact thai it 

 has in the metamorphosis-stages ophicephalous pedicellariae of the type 



12* 



