38 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 7 



Halosydna, species B 

 Plate 22, Figs. 273-279 



Collection. — 617-37. One specimen. 



A nearly complete specimen, with 32 setigerous segments, measures 

 1 7 mm long. It is pale throughout except for small brownish patches on 

 the elytra. An oblong pale area over the hilum is bounded on its inner 

 side by a sooty patch that blends gradually with the brown patches. 

 Elytra and acicula pale amber. 



The prostomium is somewhat macerated and turned under. It is 

 about as broad as long, with a shallow median sulcus. A single pair of 

 black eyes is near the posterior margin, but the anterior eyes might have 

 become obliterated through maceration. 



Elytra are fringed on their external margins, with a short, slender, 

 trim fringe (pi. 22, fig. 274). The anterior margin is slightly excavate. 

 There are no macrotubercles, but the surface is more or less uniformly 

 covered with microtubercles ; these have a circular base and a horny 

 blunt cone (pi. 22, fig. 276). In addition there are irregular blotches of 

 pigment (pi. 22, fig. 275). The entire surface is underlain by minute 

 clear areas, smaller than the tubercles and regularly distributed. 



The parapodia are subbiramous, the notopodia small, papillar, on the 

 anterodorsal face of the neuropodia. About 12 longer, slender, serrulated 

 notopodial setae project distally, beyond the middle of the neuropodial 

 setae, and there are a few shorter, blunter superior notopodial setae. 

 Neuropodia are robust, truncate distally (pi. 22, fig. 277), with longer 

 larger setae in the superior fascicle (pi. 22, fig. 278) and similar smaller 

 setae inferiorly (pi. 22, fig. 273). All are entire distally. The dorsal 

 cirrostyles extend distally well beyond the notopodial setae. 



The unique character of the neuropodial setae, with their long, 

 smooth entire tips, and the tuberculation of the elytra do not favor the 

 inclusion of this specimen with any known species of Halosydna. 



Distribution. — San Juanico Bay, Gulf of California, Mexico, in 

 24 fms. 



Genus LEPIDONOTUS Leach 



Lepidonotus nesophilus Chamberlin 



Plate 7, Figs. 83-95 



Lepidonotus nesophilus Chamberlin, 1919a, p. 75. 



Collections. -~\A^-ZA, 814-38, P273-35. 9 specimens. 



In these specimens the prostomium is clearly lepidonotoid, with a 



