54 University of California PtihUcations in Zoology [Vol. 18 



of the palpi. They are uniform in diameter with subterminal enlarge- 

 ments ending then in filamentous tips. The palpi are very stout at the 

 base, decreasing in diameter gradually and ending abruptly in 

 filamentous tips; they are deeply grooved and covered with rows of 

 prominent cilia. The peristomial cirri arising from strong cirrato- 

 phores are of equal length with the palpi. The styles of the peris- 

 tomial cirri are long, uniform in width, with subterminal bulb from 

 which filamentous tips project. 



The biramous parapodia (pi. 3, fig. 25) are comparatively stout, 

 bearing two dark acieuli. The neuropodium has numerous (40-60) 

 amber-colored setae, varying in shape and size. There are about 

 twenty supra-acicular setae (pi. 3, fig. 30) with prominent serrations 

 and a strong subterminal tooth. The 30 to 40 subacicular setae (pi. 

 3, fig. 33) differ slightly from the supra-acicular in that the sub- 

 terminal tooth is smaller or rudimentary. The notopodium is incon- 

 spicuous and bears two kinds of setae ; about 12 to 15 short, strongly 

 curved setae, covered with strong serrations and ending bluntly with 

 the proximal end and the extreme distal end smooth or free from 

 serrations (pi. 3, fig. 31), and about 20 to 30 long, fine setae, densely 

 covered with serrations, more or less curved and terminating in a fine 

 point (pi. 3, figs. 26 and 27). 



The setae from the second parapodium differ from those of other 

 parapodia in their shape and also by being more strongly serrated. 

 The notosetae (pi. 3, figs. 28 and 29) are about equal in size to the 

 neurosetae (pi. 3, fig. 32). They are also nearly alike in shape and 

 structure. 



The nephridial papillae begin on the fourth segment, being 

 situated at the dorso-lateral margin near the base of the parapodium 

 and occurring thence posteriorly on all segments. The first or 

 anterior papillae are short, increasing considerably in length dorsad. 



There are eighteen pairs of elytra (pi. 3, fig. 23) occurring on 

 segments 2, 4, 5, and on all alternate segments to 27, then on seg- 

 ments 28, 30, 31 and 33. They are comparatively thin and smooth, 

 with but a few small, scattered papillae and are mottled with dark 

 brown or black pigment (pi. 3, fig. 24). There are no marginal 

 cilia. Fine venations radiate from the elytrophore in all directions. 

 The dorsal cirri are equal in size and shape to the peristomial cirri. 



Comparison. — The species resembles Halosydna carinata Moore 

 (1903) in some respects and this is specially true of the broad pro- 

 stomium and the conspicuously grooved palpi. The chief difference 



