91 



larvae, where it is always found in a horizontal position; hul I hi- fact that 

 there is a piece exactly corresponding to it on Hie ventral side makes I lie 

 homology more doubtful. The question must remain unsettled for the 

 present. 



Species f (PI. XIII, Figs. 3 1, Textfigure 3(>). One specimen was 

 taken off Minicoy (Malclive Islands; 7.", K, 7 X.; 26/IV. 1900), another in 

 the Bay of Bengal (89 K. <> X.; 5/1. 191-1). Both specimens are in begin- 

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

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



Fig. 36. Skeleton of Kcliinoplitleus Iran.wrmis. species f. Seen from the rlors;il side. "">/,. 



Letters as in Fig. :U. 



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 differences. That 

 they are, however, really different 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 which Kchinoids these remarkable larvas 

 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. I ha I 

 it was probably the larva of Echinoinclni luninlcr. The fact that it 

 has in the metamorphosis-stages ophieephalous pedicellariaa of the type 



12* 



