32 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 7 



Genus HALOSYDNA Kinberg, emend., Hartman 



Body moderately short, depressed; number of setigerous segments 

 about 36; number of elytra 18 pairs (or rarely 19), distributed on seg- 

 ments 2, 4, 5, 7, 9, . . . 27, 28, 30, 31, 33 (or rarely also on 34). 

 Notopodial setae shorter and slenderer than neuropodial setae, serru- 

 lated. Neuropodial setae with a distal enlargement, the tip entire or 

 bifid, the expanded portion with transverse rows of serrations. (See 

 Hartman, 1938, p. 109, for synonymy.) 



Halosydna fuscomarmorata (Grube) 

 Plate 9, Figs. 119, 120 



Polyno'e fuscomarmorata Grube, 1875, p. 62. 



Halosydna fuscomarmorata Augener, 1906, pp. 117-119, pi. 3, figs. 41- 

 44; Monro, 1928a, pp. 566-567. 



Collections.— ?>9\-Z5, 380-35, 414-35, 437-35. 5 specimens. 



Length to 25 mm (egg-laden individual). The dorsum, including 

 the elytra, is dark bluish gray, the ventrum paler; setae are amber 

 colored. The prostomium has four small eyes so placed as to be almost 

 visible in dorsal v'ltw. Elytra are smooth, with a characteristic dark, 

 marmorated pattern, deepest in the area over the hilum, but leaving a 

 pale or white spot over the area of attachment (pi. 9, fig. 119). Micro- 

 tubercles are distributed chiefly along the anterior margin but a few are 

 scattered over the entire surface (see also Monro, 1928a, p. 567). 

 Neuropodial setae are distinctly bifid at their distal end, and the ser- 

 rations increase in size distally (pi. 9, fig. 120). 



Distribution. — Peru, Colombia, Panama. Intertidal to 3 fms. Seid- 

 ler (1924, p. 120) erroneously reported this from the West Indies. 

 Since this record is based on Grube's type, it should be Peru. 



Halosydna latior Chamberlin 



Halosydna latior Chamberlin, 1919b, pp. 1-2; Hartman, 1938, p. 110. 

 Halosydna obtusa-cirrata Treadwell, 1937, pp. 143-144, pi. 1, figs. 8-11. 



Collections. — ^Acc. 525, Ace. 542, Ace. 585, Ace. 622. 10 specimens. 



Distribution. — Southern California to Lower California, Mexico. 

 Low intertidal to 40 fms. H. obtusa-cirrata Treadwell was described 

 from east of Cedros Island, Lower California. This is the same as 

 Cerros Island, on the outer side of Lower California, along the northern 

 half of the peninsula. 



