296 



U.S. NATIONAL MUSEUM BULLETIN 227 



Description.' — Length? (more than 12 mm.), width up to 2 mm., 

 segments? (more than 28). Body elongate, cyHndrical, wider and 

 flattened in anterior thoracic region, tapering slightly posteriorly. 

 Prostomimn and buccal segment suboval, about as wide as long, 

 rounded anteriorly or slightly pointed, without antenna or eyes, with 

 a pair of nuchal folds projecting above first setiger and lateral to the 

 tentacular palps. Tentacular palps very long (may be longer than 

 the body, according to Eliason), with a longitudinal groove. The 

 palps are contractile and deciduous; thus they are variable in length 

 when contracted or regenerating (fig. 77, a,b). First setiger extended 

 forward ventrally forming lateral and lower lips for the mouth. 

 Proboscis eversible, short, globular, disclike (not lobed). 



intC — 



neS 



Figure 77. — Apistobranchidae, Apistobranchus iullbergi: a, dorsal view anterior end; h, 

 same, ventral view; c, parapodium from setiger 2, posterior view; d, neuroseta from 

 same; e, parapodium from setiger 4, posterior view; /, neurosetae from same. 



