CEPHALANA. 



99 



Diplotis (Mont). Body gelatinous ; front trun- 

 cate, with two ear-like tentacles ; attenuated behind, 

 and slightly three-pointed. 



D. hyalina. Fig. 162 ; mag. |. 



161 



162 



SUB-TKIBE III. CEPHALANA. 



Segments equally provided with appendages ; 

 no shield-plates. 



Jaws not exceeding one or two 

 pairs ; gills none, or in the form of 

 lobes, or simple leaves, inserted at 

 the top of the foot ; aciculi present. Nereidce. 



Seven to nine pairs of horny, 

 jointed jaws ; gills (when present) 

 in the form of pectinated filaments, 

 inserted above the dorsal cirrus; 

 aciculi present 



No jaws ; gills greatly developed, 

 in the form of shrubs, tufts, or 

 plumes, inserted on the back, at 

 the base of the foot ; no aciculi. . 



