128 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 22 



Santa Barbara Point Light, in 37 fms, in sediments of green clay, shows 

 the maximum development of ovigerous development, and the relations 

 of setae and branchiae (Plate 12, fig. 2). It is possible that individual 

 segments are shed as ova mature, and that gonadial development pro- 

 ceeds more anteriorly. 



Tharyx monilaris is at once distinguishable from other species of the 

 genus by its small size; setae are entirely slender and hairlike; both 

 anterior and posterior ends are inflated, and median body segments are 

 moniliform. It has been found generally distributed in shelf, slope and 

 basin sediments, and is often present with T. tesselata (unpublished 

 records). 



Genus COSSURA Webster and Benedict, 1887 

 Cossura Candida Hartman, 1955 

 Hartman, 1955b, pp. 44-45, pi. 1, figs. 1-5. 



Many collections come from San Pedro, Santa Catalina, Santa Cruz, 

 San Nicolas, San Clemente, East Cortes and Velero Basins, and from 

 San Diego trough. The single median tentacle is inserted on the third 

 setigerous segment. The species is more widely known from shallower 

 ocean bottoms off southern California. 



Cossura sp. 

 A small dark red specimen was taken in Santa Catalina Basin and a 

 similar one in San Nicolas Basin. Both lack posterior ends; their specific 

 determination is not possible. 



Family FLABELLIGERIDAE 



Three species in three genera are represented; they are distinguish- 

 able according to the following key. 



Key to species 



1. Setae of first several segments form a cephalic cage 



Pherusa sp. 



1. Without a cephalic cage 2 



2. Surface epithelium smooth; some setae falcigerous (Plate 14, 

 fig. 1) Brada glabra 



2. Surface epithelium densely papillated (Plate 13, fig. 1); setae 

 distally pointed (Plate 13, fig. 2) . . Ilyphagus ilyvestis 



