NO. 2 H ARTiM AN : QUANTITATIVE SURVEY 205 



ventral lobes resembling the dorsal lobes. In damaged, or regenerated 

 specimens these lobes may be otherwise. 1 he thoracic membrane is re- 

 duced. The first, or collar, fascicle emerges from the dorsalmost part of 

 the collar membrane; its setae are in thick, projecting tufts; each seta is 

 simple and bayonet-shaped. Segments two to five have smaller notoseta 

 fascicles and neurosetae in transverse, linear ridges; the uncini form a 

 single row of many Hat platelets; each uncinus (Fig. 3) consists of a thin 

 rectangular base with a series of twelve teeth along the cutting edge. 



1 he thorax is separated from the abdomen by a long, smooth, apodous 

 region. Abdominal segments are very short, appear crowded, have short 

 uncinial ridges and inconspicuous setal tufts. Abdominal uncini are 

 smaller than thoracic vmcini, and each has about seven marginal teeth. 

 Tubes are fully attached to the substratum; they measure about 7 mm 

 across, with the lumen only about 2.5 mm across. Mature females are 

 bright orange red, males pale; the opercular stalk is deep maroon to 

 brown, splashed with white. 



Distribution : Long-shore islands of southern California, on rocky 

 surfaces in low intertidal or littoral zones. 



ANALYSES, BY AREAS 



T he San Pedro region is divided into areas which are believed to have 

 unique biological characteristics. Nearly a third of the region is taken 

 over by the San Pedro Basin ( Hartman and Barnard, 1958, 1960). Sub- 

 marine canyons include the San Pedro sea valley, the Newport canyon 

 (Hartman, 1963), and the San Gabriel sea valley (see ALip 1). The 

 following areas are here further identified : 



LH refers to the Los Angeles-Long Beach outer harbor, a shallow 

 enclosure bounded on the east by the mainland, and on the west by an 

 artificial breakwater. 



PV refers to the Palos Verdes shelf and slope, bordered on the east 

 by the Redondo canyon, on the west by the sill of the San Pedro Basin, 

 and on the south by the San Pedro sea valley. It is the site of an important 

 outfall line for Los Angeles County. 



SP refers to the San Pedro shelf and slope; it is bordered on the east 

 by the Los Angeles-Long Beach breakwaters, on the south by the New- 

 port canyon, on the north by the Palos Verdes shelf and slope; on the 

 west it surrounds the Lasuen sea mount and Sixmile bank, then continues 

 seaward to the Catalina rise. 



