POLYCHAETE WORMS, PART 1 137 



Dorsal cirri about length of setal lobes, basal portion globular, distal 

 portion cylindrical (fig. S5g). Form sexual epitokes; male epitokes 

 with swimming setae beginning on about sctiger 7 (7-11) ; females with 

 eggs and embryos attached vcntrally to parapodia, 2 to 4 per segment, 

 beginning on about setiger 7 (7-8). 



Biology. — Found at low water in mud, on algae, sponges, shells, in 

 Laminaria holdfasts. In Ireland region, mature specimens with swim- 

 ming setae found from May to October (Southern, 1914). 



Material examined. — Three slides of specimens identified as S. 

 brevifrons by Webster and Benedict, presumably from South Norwalk, 

 Connecticut. 



Distribution. — British Isles, France, Mediterranean, Black Sea, 

 Connecticut, west coast Vancouver Island, Mexico. Low water to 

 16 fathoms. 



Genus Autolytiis Grube, 1850 



Polybostrichus Oersted, 1843; type (raonotypy) : Polyhoslrichus longosetosus Oer- 

 sted, 1843; = male stolon Autolijhis sp. 



Sacconereis M. INIiiller, 1855; type (monotypy) : Sacconereis helgolandica M. Miiller, 

 1855; = female stolon Autolyius prolifer (O. F. Muller, 1788b). 



Proceraea Ehlers, 1864; type (monotypy): Proceraea picta Ehlers, 1864. 



Stephanosyllis Claparede, 1864; type (monotypy): Autolytiis {Stephana syllis) 

 scapularis Claparede, 1864; = Autolytiis pictus (Ehlers, 1864). 



Type (original designation) : Autolytus prolifer (0. F. Muller, 1788b). 



The species represented have the body of the stem form thin, elon- 

 gate, widest anteriorly, attenuated posteriorly, flattened ventrally, 

 arclied dorsally. Prostomium (fig. 3S,a,b) suboval, with palps 

 poorly developed, fused, turned ventrally, forming a thin rim pro- 

 jecting a variable distance be3''ond the head, with 4 eyes in trape- 

 zoidal arrangement (may be an additional minute anterior pair near 

 the bases of the palps). Antennae, tentacular cirri and first 1 or 

 2 pairs of dorsal cirri long, filiform, longer than the rest of the dorsal 

 cirri, smooth or faintly annulate, often curled. Median antenna 

 and first pair of dorsal cirri longest, lateral antennae and upper pair 

 of tentacular cirri next in length, lower pair tentacular cirri shorter. 

 Nuchal epaulettes or dorsal ciliated ridges more or less developed. 

 Neuropodia short, bulbous, without ventral cirri (fig. 38c). 



Proboscis rather long, more or less sinuous, with chitinous lining 

 with a crowm of teeth. Reproduction by stolons which differ from the 

 stem form and are sexually dimorphic. Each species, then, has three 

 types of individuals: Stem form which buds off asexually male or fe- 

 male stolons, singly (fig. 38a) or in chains (fig. 40a) ; male stolons or 

 polybostrichus stage; female stolons or sacconereis stage. 



Female stolons or sacconereis stage (fig. 39, 406) : Head suboval with 

 2 pairs of eyes, a larger ventral pair and a smaller dorsal pair, with 3 



