by these points. The posterodorsal rods have just appeared: I hey arc 

 t'enestrated. The dorsal arch has a very long posterior process; Ihe fad 

 of its appearance al Ihis comparatively young slage would seem lo indicate 

 that the arms, except the posloral ones ( they are broken in the spe- 

 cimen, so that their exact length cannot be ascertained; but they are 

 fairly long, anyhow ) are, upon the whole, short. The anterolateral 



Fig. 11. Skeleton of the larva of To.ropneusles roseus (?). */,. Letters as in tig. 5. 



arms (they are broken, but somewhat restored in the figure) are evidently 

 short. The posterior transverse rod has not yet appeared. The body 

 skeleton is nearly smooth (Fig. 11). 



Pseudocentrotus depressus (A.A.). 



As the breeding season of this species did not occur during my slay 

 in Japan (April July), I could not study its development myself. Being, 

 however, very anxious lo learn, whether the larva of this species would 

 prove to be of the same type as the other Toxopneuslids, as I expected, 

 or perhaps of the Echinus-Strongylocentrotus type, 1 asked my Japanese 

 colleagues to do me the service lo try to rear the larva, when its breeding 

 season came on. Dr. Fuji ta, then Assistant at the Biological Station 

 of Misaki, kindly undertook lo rear the larva, when in the end of Oc- 

 tober ripe specimens of Ihe species were round. The preserved larva' 

 were sent lo me and received in February I'.llii'in Panama. On exami- 

 ning them I found my expectations confirmed: Ihe body skeleton formed 

 a basket structure as in the Toxopneuslid;e (i. e. most of them, Li/lcclii- 

 nus forming a remarkable exception). The closer sludy of the larvae, 

 which were reared only till the first slage (Ihe oldest being 10 days old). 



