SOME JAPANESE ECHIKODERMS. 



545 



Irotus depressus ; but this point must be left to one of my Japanese 

 colleagues to ascertain. 



In the later stages of Strong, pulcherrînius-iaxvœ, the long body 

 rods are resorbed and the body shortened, just as in Echinus larvae. 

 (It is with purpose that I do not say ' as in Strong, droebachiensis 

 larvae.' It is true Agassiz has described the complete development 

 of this species, but, as I have already shown in my first paper on 

 Echinoderm-larvae [„Die Echinodermenlarven d. Plankton-Expedi- 

 tion "], he has there confounded other larvae with those of that 

 species). In the latest stages reached, the larvae had just begun to 

 show signs of approaching metamorphosis ; but vibratile epaulettes 

 had not yet formed. If they form at all in this species is a question 

 I am sorry I must leave undecided. (In the larva of Strong, 

 droebachiensis there are epaulettes ; I can say this, having obtained 

 some larvae in Plankton samples from Greenland, where no other 

 Echinoid occurs, making the correctness of the identification of those 

 larvae beyond the reach of doubt). The rods of the processes are all 

 simple, not fenestrated. 



Toxocidaris tuberculatum. — The larva of this species is quite 

 different in body shape and in the structure of skeleton from that of 

 Str. pulc'herrimus. In the first stage it is similar to that of Toxo- 

 pneustes pileolus : the body is short, and the skeleton of the body 

 forms a frame, the 

 rods being very 

 strongly thorny. 

 In a later stage, 

 a posterior cross- 

 rod is developed, tr- 

 ending in two very 



peculiar postero- 

 Fi g. 1.— Posterior cross-rod and postero-lateral rods of 



lateral rods, which 300 



the larva of Toxocidaris tubercttlatus. — — 



are strongly thorny 



