NO. 4 hartman: spionidae from California 313 



Spionid larva 



Plate 48, Figs. 50-53 



During April and May, 1938, a small, spionid larva was encountered 

 many times in plankton taken from the pier of the Scripps Institution. 

 This differed from all other spionid larvae in having a conspicuously 

 prickly pygidium, hemispherical in shape (pi. 48, figs. 51, 52). It lacked 

 pigment except for 4 dark eyes on the prostomium and yellow alimentary 

 tract. Like other spionid chaetigers, when disturbed, it thrust its setae 

 laterally; this is also the position assumed when fixed (pi. 48, fig. 50). 

 In life the long, larval setae were directed posteriorly or laterally. In 

 addition to prototroch and telotroch, there were paratrochs on the third 

 and fifth setigers. A 9-segmented larva had bifid hooded hooks (pi. 48, 

 fig. 53) in neuropodia of segments 8 and 9, 2 in each foot of segment 8, 

 and 1 in each of the ninth. All other segments had smooth capillary setae 

 only, those of the first 2 segments the longest. 



Only a few spionids are known to have a papillated pygidium ; none 

 has been recorded from western America which agrees with the conditions 

 in this larva. 



