APPENDIX TO CHAPTER X 



APPENDIX TO CHAPTER X 



159 



i 



KEY TO THE MORE IMPORTANT FAMILIES OF POLYCH^TA 



a\. Head distinct from trunk ; proboscis protrusible 



[wandering Polychseta]. 

 bi. With broad dorsal scales . ; . 



&2- No scales ; only one mouth-segment. 



d. Cirri not leaf-like ; body long and not 



flattened. 

 d\. Head not segmented. 



ci. Jaws composed of many pieces . 

 62- Two powerful jaws . 



<? 2 . Head with its lobes segmented . 

 c 2 . Small worms, body flattened, cirri evident 



2 . Head not distinctly separated from trunk ; pro- 

 boscis short, not protrusible ; no jaws [seden- 

 tary Polychseta]. 

 bi. Gills, when present, arise either from almost 



all, or else the middle segments. 

 Ci. Body not separated into various regions ; 

 distinct head ; no antennas ; gills in 

 form of elongated, thread-like cirri 



C 2 . Body divided into 2 or 3 different regions ; 

 no antennal cirri ; proboscis present ; 

 no gills . . . . 



6 2 . Gills almost always present and limited to the 



anterior end of the body ; no cirri ; body 



divided into an anterior and a posterior part. 



GI. Gills confined to the anterior segments ; 



head lobe small ; numerous antennas in 



2 bunches ; no antennal cirri 



c 2 . Gills confined to head ; 2 inrolled leaves 

 standing at the sides of the mouth 



Aphroditidce 



(Ex. Lepidonotus) 



Eunicidas 

 Nereidai 



(Ex. Nereis) 



Glyceridce 



(Ex. Euglycera) 



Syilidce 



(Ex. Autolytus) 



Cirratulidce 



(Ex. Cirratulus) 



Maldanidce, 

 (Ex. Clyuienella) 



Terebellidce 



(Ex. Amphitrite) 



Serpulidce 

 (Ex. Serpula) 



