12 



and truncated posteriorly; the postoral rods are simple, and the body 

 skeleton forms no basket structure (Fig. 9). The branches at the end 

 of the body rod, as also the recurrent rods are rather strongly thorny 

 distinctly more so than in the larva of L. anamesus. The larva is very 

 transparent, willi a small duster of red pigment cells in tlu' point of each 

 arm and a few cells of the same colour spread irregularly in the body. 



At the age of 11 — 12 days the larvtr showed the beginning 

 formation of the vibratile lobes; after this they did not develop 

 any further and soon died. I can thus give no information 

 about the .shape and skeletal structure of the fully formed 

 larva. Especially it would be important to know whether 



Fig. 0. Skek'loii ol tlu' l;iiv:i ol l.ylcchiniis [)anamenf:is. A. Iidiil %'iew; B. side view. '"7i- 

 Li'tlcMs as ill fig. 5. vtr. ventral liaiisviTse rod. 



epaulets and the posterior transverse rod are j)resent (as is lo be ex- 

 pected) or not. But, anyhow, the fact here made known thai the laiva 

 in its first stage is in perfect accoidance with that of L. iniricudliis and 

 anamesus (+ piclus) is of considerable interest. 



Lytechinus verruculatus (f.lU.) 



lu the beginning of .\pril lOl.') I undertook repeatedly fertilization of 

 this species during my stay at Hilo, on the island of Hawaii. 



The eggs are small (1 have no measurement of Ihem) and vi'iy clear. 

 The cleavage proceeds at an extraordinary speed, so that already four 

 hours after fertilization the blastula stage is reached (though not yet 

 swimming); the embryos are very transparent and form an excellent 

 object for nncroscopical study. The hrsl larval stage has the usual shape, 

 with the posterior end short and truncated. The body skeleton forms 



