47 



has a slight siiuialion in the middle. Over the whole body, as well as 

 along the vihialile band are scattered refi-brown pigment cells; in the 

 end of the arms and in the posterior end of the hotly they may be lying 

 somewhat closer, but there is never a very prominent pigment spot in 

 the end of the arms. — The skeleton is simple. There is no basket-structure 

 and not even an indication of a recuireiil rod. The body rods are club- 

 shaped, with some irregular, short branches at the thickened end. Other- 

 wise the skeletal rods are very slender and very linely Ihoriiy. (Fig. 12). 



At the age of ca. 

 .'i weeks the postero- 

 dorsal arms luid \)r- 

 gun to appear, Lheir 



supporting rods 

 being also simple 

 and very slender. At 

 the age of one month 

 the posterior end of 

 the body rods showed 

 signs of beginning 

 absorption: the dor- 

 sal arch had ap- 

 peared and the pre- 

 oral arms had begun 

 to develop. A small 

 vesicle lying opposite 

 the hydrocoel on the 



left side evidently l-lg. 12. SkcMon o\ Ihe larsa oi Slrongytocentmlus puUlierrimus. 

 represented the be- l**' stage, a. ventral view, B. Side view. "Vi- I-etters as in fig. 5. 

 . . . r vtr. ventral transverse roH. 



gmning amnion-for- 



mation. At five weeks the body rods had been almost completely ab- 

 sorbed. There was otherwise no change — no poslerioi- transverse rod 

 and no epaulets. The larva- still lived for nearly two weeks more, but 

 they did not develoj) any fiirtiier. The (jtiestion whether epaulets are 

 present in llie ftilly developed larva of this s|)ecies thus still remains 

 open. No new (■iiiliire of litis species could be obtained al that time, its 

 i)ieeding season i)eing over. 



Tile larva of .S7/'. drobarhiensis was reared by Agassi/ till the age 

 of 1 weeks. The i)ostero-dor.sal arms and the dorsal arch had appeared, 

 btil a|)paieiitly lie has not observed any beginning absorption of the body 

 rods. .\s for the later stages described and figured by Agassi/, as be- 



