POLYCHAETE WORMS, PART 1 135 



less. Females with large eggs, one per segment, attached ventrally 

 on setigers 14 to 29 or so. 



BiOLOGY.^ — Found at low water, in muddy-sandy flats and on 

 Diopatra tubes. Dredged on muddy bottom. Females with eggs 

 attached to body were found in October (Buzzards Bay, 10 fathoms, 

 October 20, 1956, N. Riser). 



Material examined. — Massachusetts (Wellfleet Harbor, Cape 

 Cod; Chappaquoit; Buzzards Bay, 10 fathoms, N. Riser). 



Distribution. — Massachusetts. Low water to 10 fathoms. 



Genus Sphaerosyllis Claparcdc, 1863 



Type (designated by Hartman, 1959a, p. 222) : Sphaerosyllis 

 hystrix Claparede, 1863. 



Both species are tiny, threadlike, with body linear, tapering 

 slightly anteriorly and posteriorly, oval in cross section. Body, 

 including parapodia, covered with small papillae and incrusted with 

 fine granular material. Prostomium subrectangular, much wider tlian 

 long. Antennae subequal, bulbous basally, narrower distally; median 

 antenna attached posteriorly on prostomium, lateral antennae anterior 

 in position; palps fused basally. 



Tentacular segment not distinctly set off from the prostomium 

 (the prostomium may be pulled back within the tentacular segment so 

 that the single pair of tentacular cirri may appear to be anterior to or 

 on the same level with the median antenna) ; tentacular cirri shnilar to 

 the antennae. Neurosetae of 2 kinds: Single, long, simple tapering- 

 upper one; compound setae with distal blades entire, hooked. Dorsal 

 cirri similar to the antennae, lacking on setiger 2. Ventral cirri 

 digitiform, shorter than the setal lobes. Anal cirri 2, larger than the 

 dorsal cutI. Proboscis wdth a single anterior tooth. 



Key to the New England Species of Sphaerosyllis 



1. Prostomium with 6 eyes — 2 larger pairs in transverse line or slightly concave 

 arc and 2 small anterior ocular spots (fig. 35a). Parapodia without 



capsules of rodlike structure S. erinaceus 



Prostomium with 4 eyes in rectangular arrangement. Basal part of parapodia 

 with rounded capsules filled with small rods, beginning on setiger 4 (fig. 

 35(7) S. hystrix 



Sphaerosyllis erinaceus Claparede, 1863 



Figure 35a 



Sphaerosyllis brevifrons Webster and Benedict, 1884, p. 714, pi. 3, figs. 24-30; 1887, 



p. 720.— Miner, 1950, p. 292, pi. 9G. 

 Sphaerosyllis lonqicauda Webster and Benedict, 1887, p. 720, pi. 3, figs. 35-39. 

 Brania sp. Hartman, 1944a, pi. 24, figs. 1-2. 

 Sphaerosyllis erinaceus Pettibone, 1954, p. 255, fig. 2S)n; 1956a, p. 555. — ? Day, 



1954, p. 13, fig. 2,e-6f.— Uschakov, 1955, p. 190, fig. 55.— Banse, 1959, p. 434. 



