118 



On the 19th of February I left Wellington and then carried the culture 

 onboard the steamer to Sydney. The young larvae apparently not being in 

 the very best condition, as they were mostly lying on the bottom of the 

 dish I undertook to change the water of the culture onboard,^ which could 

 not be done without some amount of trouble ; but it proved to have good 

 results; the larvae now again appeared healthy, and they went on devel- 

 oping normally. On the 3rd of March, 15 days after fertilization, they had 

 formed the dorsal arch and were evidently near metamorphosis. I now left 

 Sydney for an excursion of some days and on my return I found the 

 culture dead, evidently because of the excessive heat of those days. But, 

 anyhow, valuable information about the larva of this Echinoid was ob- 

 tained. There was no opportunity of making drawings of the living larvae 

 and, to my great disappointment, the skeleton had been dissolved in all 

 the preserved specimens. Fortunately 1 had made a free hand sketch of 

 the larval skeleton so that 1 am able to give information about the main 

 features of the skeletal structure of this larva. 



The shape of the larva (PI. XI, Figs. 4—5) in general recalls that of the 

 Clypeastroid larvae. The body is short in accordance with the fact that the 

 body rods are not especially elongated. The arms are all broad and flat, not 

 very long; still they are in all probability normally somewhat longer than 

 shown in PI. XI, Fig. 5. One of the preserved specimens has one of the post- 

 oral and one of the anterolateral arms somewhat longer, 

 which would tend to show that they have not attained 

 their full length in the specimen figured. There is a pair 

 of vibratile lobes on the ventr&l side, but none on the 

 dorsal side, at least not in any of the preserved spec- 

 imens, whereas there is a pair of small posterolateral 

 lobes. The body is somewhat widened on the dorsal side 

 at the level of the preoral band. The anterolateral arms 

 are of unequal length in the preserved specimens, which 

 may perhaps be a normal feature of the larva. The pre- 

 oral arms are quite short in all the specimens. Some hght 

 yellow pigment was found in the point of the arms, the 

 Fig. 50. Skeleton larva being otherwise unpigmented 



:w.:™11f:r;; J^^'. ^^^^^^°" (^^g-^O) ^ecaUs the Clypeastroid type; 

 view. After a free ^'^^^^ ^^ ^ well developed recurrent rod, sUghtly widened 

 hand sketch from at the end, as is also the body rod; the processes from 

 Letters as'in fig. 51. *^^^^ ^°^'' however, do not join so that no true basket 

 structure is formed. The rods of the arms are simple 

 It IS a noteworthy fact that the larvae on being preserved in alcohol 

 turn green, as do the Clypeastroid larv*. Also the adult specimens have 



