COMPLETE HARTMAN: POLYCHAETES FROM CALIFORNIA 75 



dark brown, smooth, has short parapodia and cirri, and is easily over- 

 looked. Length is about 4 mm ; width 0.3 mm ; number of segments 

 about 48. Preserved specimens are usually nearly straight, linear or 

 somewhat coiled in their posterior end. When retracted, the esophagus 

 is visible through the body wall in segments 1 to 3, and the cylindrical 

 gizzard in segments 4 to 8 (PI. 8, fig. 1). The prostomium is wider 

 than long, rectangular, has 4 small eyespots on its posterior half, with 

 the 2 of a side far apart and near the outer ectal margin of the lobe. 

 The large, fused palpi are directed forward, together longer than wide, 

 and the anterior end bluntly conical (PI. 8, fig. 1). The first segment 

 lacks cirri or parapodia ; it is a smooth ring behind the prostomium. 

 The second segment is the first setigerous. All parapodia are small, 

 lateral, provided with composite setae. Ventral cirri are short, conical 

 lobes, without special structure. The body terminates posteriorly in a 

 pair of lateral, spherical processes (PI. 8, fig. 3) at the sides of the 

 anal pore. 



Setae are entirely composite; the uppermost are long appendaged 

 spinigerous (PI. 8, fig. 4) and the lowermost are short appendaged 

 falcigerous (PI. 8, fig. 5) ; they number about 5 in a parapodium. The 

 shaft is widened distally and oblique, to accommodate the base of the 

 appendage. The superiormost have an appendage with cutting edge 

 deeply dentate, with about 20 oblique teeth (PI. 8, fig. 4) ; the lower- 

 most are much shorter, with teeth numbering 3 or 4 (PI. 8, fig. 5). 



Exogonella brunnea may be more abundantly present than present 

 records indicate ; it is so small that it passes through the mesh of screens 

 employed in quantitative studies. 



Genus Plakosyllis Hartman-Schroder, 1956 

 Type P. brevipes Hartman-Schroder, 1956 



Plakosyllis americana, new species 

 Plate 33, fig. 1 



Collection. Sta. 5768 (5 specimens). 



The type is selected from Velero IV Sta. 5768, 10^2 mi from Point 

 Loma, California, in 18J-4 fms, sediment of red sand. The longest indi- 

 vidual measures 4 mm long by 0.9 mm wide and consists of 75 to 100 

 segments. The body is very flat, depressed, and resembles that of an 

 elongated spintherid ; its form suggests that the species may be com- 

 mensal. All antennae, tentacular and dorsal cirri and anal appendages 

 are globular, and ventral cirri are short and triangular. 



