POLYCHAETE WORMS, PART 1 209 



Superfamily Glycerea 



Includes Glycoridae and Goniadidae. See the key to the families, 

 p. 9. 



Family Glyceridae 



Body rounded, long (short compared with Goniadidae), smooth, 

 fusiform, tapering gradually toward both ends. Body not divided 

 into 2 regions (as in Goniadidae), either with only uniramous (Hemi- 

 podus) or only biramous parapodia (as Glycera). Segments biannu- 

 late or triannulate. Prostomium (figs. 53, a,b; 55a) small, sharply 

 conical, transversely annulated. The distal ring with 4 minute, usually 

 biarticulate antennae. The basal ring longer (peristomium fused 

 with prostomium), with a pair of nuchal organs (appear as slits or, if 

 everted, as papillae). With or without minute eyes in basal and 

 distal rings. 



First 1 or 2 segments usually with rudimentary uniramous para- 

 podia. Uniramous parapodia supported by single aciculiun with only 

 compound spinigerous setae. Biramous parapodia (fig. 53, c-/) with 

 rami poorly separated, supported by 2 acicida, the upper one with a 

 group of simple notosetae, the lower one with compound spinigerous 

 neurosetae arranged in a fan-shaped group. Dorsal cirri small 

 globular; ventral cirri larger, conical; two anal cirri (fig. 556). 

 Branchiae present or absent; when present, they are thin-walled 

 coelomic extensions; they may be saclike or digitiform, stationary or 

 retractile, simple or branched. The branchiae are ciliated within, 

 causing a streaming of the coelomic red blood cells toward the outside 

 and tossing around in the center. 



Proboscis (fig. 55,a,d,e) long (short compared to Goniadidae), 

 strong, muscular, clavate, armed distally with 4, equally-spaced, large, 

 dark, hooked horny jaws or paragnaths each with an attached 

 embedded rodlike aileron. Surface of proboscis covered with numer- 

 ous, crowded, small, nearly uniform papillae or proboscideal organs, 

 giving a velvety aspect. The proboscis is a remarkable organ, serving 

 the glycerids as an organ of special sense, with a remarkably well 

 developed nervous system (Gravier, 1898). 



Epitoky ( swarming at maturity ) has been described for a few 

 species. When sexually mature, the entire individual becomes 

 modified to form a swimming epitokous form, leaving the bottom and 

 swimming actively at the surface. 



The body may go through considerable changes associated with 

 epitoky: The proboscis degenerates and is cast off, the intestine is in 

 large part resorbed, and there may be a certain amount of muscle 

 atrophy of the body wall. The parapodial lobes become elongated 

 and the setae are elongated and augmented in nmnber, some simple 



