126 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 22 



lied, they are distally slightly curved and terminate in a tip with 3 or 

 more shallow serrations. 



Caulleriella gracilis was first described off Santa Catalina Island in 

 over 2000 fms. It is more widely distributed in shallow bottoms of 

 western Canada (Berkeley and Berkeley, 1950) and southern California. 



Genus THARYX Webster and Benedict, 1887 



Tharyx tesselata, new species 

 (Plate 11, figs. 1-4) 



Numerous specimens were taken in San Pedro, Santa Catalina, San 

 Nicolas, East Cortes and Long Basins and from Patton escarpment and 

 San Diego trough. The type was selected from Sta. 5563, 13 miles from 

 Point Conception light, in a depth of 39 fms, sediments of green mud. 

 Many other specimens come from other shelf and slope depths of southern 

 California. 



Length of a larger specimen is 50-55 mm; width is 2 to 2.5 mm; 

 segments number 200 or more and are closely crowded. The prostomium 

 is long triangular and lacks eyes. The first 3 segments form the buccal 

 region ; they are smooth complete rings without parapodia or setae. The 

 first 33 setigerous segments are very short and crowded ; they have lateral 

 biramous parapodia in which notopodia and neuropodia are separated by 

 a short distance, about equal to that of the length of the setal ridge. 



In many specimens, the long paired palpi are broken off near the 

 base ; their place of attachment is in the segmental groove preceding the 

 first setigerous segment, in dorsolateral position and above the notopodial 

 position (Plate 11, fig 2). The branchiae are long lateral filaments, 

 emerging from the body wall directly above the notopodial base; there 

 are never more than a pair to a segment and they occur irregularly, so 

 that one or both of a pair are absent from some segments. 



Notopodial setae are very long, slender, hairlike; they occur in full 

 dense tufts through anterior and middle regions of the body and diminish 

 in number and length in far posterior segments. The accompanying neuro- 

 podial setae are shorter and fewer in number in median and posterior 

 segments, where they are also slightly geniculate and distinctly serrated 

 at the cutting edge (Plate 11, fig. 4). In posterior parapodia the upper 

 fascicle of setae includes about 10 to 15, and the lower one about 10 to 12. 



In preserved individuals the posterior end of the body is characteristi- 

 cally inflated (Plate 11, fig. 3) and terminates in a constricted pygidial 

 ring with dorsal anal pore. 



