COMPLETE HARTMAN: POLYCHAETES FROM CALIFORNIA 93 



As in the preceding species, the prostomium is truncate at its frontal 

 margin. There are 4 eyes in quadrate arrangement, located between the 

 palpal bases. A large, circular dark spot is located on the anterior third 

 of the prostomium. Branchiae, designated dorsal cirri in the original 

 account, are present from the second setigerous segment ; they increase 

 in length and width posteriorly, becoming long and straplike, and are 

 present throughout the rest of the body. Notopodia are provided with 

 pointed setae only. Neuropodia have setae in the first 1 1 segments and 

 hooded hooks from about the twelfth segment. The hooks have a large 

 fang slightly more than right angled to the main shaft; this is sur- 

 mounted by 3 smaller teeth in tandem, with the distalmost tooth the 

 smallest. In antero-median segments there are 10 to 12 hooks alternating 

 with as many pointed setae ; in posteriormost segments the numbers 

 decrease somewhat. The pygidium terminates in one pair of longer, and 

 another of shorter, cirriform processes. 



Nerinides pigmentata was first described from Newport Bay, Cali- 

 fornia, in silty or mixed sediments ; it occurs more widely in shelf depths 

 of southern California, in silts and shelly bottoms. At VELERO IV 

 Sta. 5869 it was associated with 50 species of polychaetes numbering 

 410 specimens, of which the most numerous were Onuphis nebulosa 

 Moore, Chloeia pinnata Moore, Lumbrineris cruzensis Hartman, Noto- 

 mastus tenuis Moore, Tharyx tesselata Hartman, Prionospio mahngreni 

 Claparede and P. pinnata Ehlers. 



Genus Prionospio Malmgren, 1867 



Type P. steenstrupi Malmgren, 1867 



Prionospio pygmaeus, new species 



Collections. The type is selected from VELERO IV Sta. 2311 

 (50 + , some ovigerous) ; others are from Stations 2505, 4862, 5531 

 and from shelf depths of southern California. 



This is one of the smallest species of the genus. Total length of 

 ovigerous individuals is 7 to 8 mm; width is 0.3 mm, and number of 

 setigerous segments 46. It is not to be confused with Prionospio malm- 

 greni Claparede, with which it may occur (Hartman, 1955a, p. 77). 

 The prostomium is longer than broad, has a straight frontal margin and 

 tapers slightly back to the bases of the palpi, where it narrows to a 

 slender ridge and extends to the second setigerous segment. The peris- 

 tomium is prolonged forward as a pair of lateral lobes at the sides of 



