422 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 10 



therefore referred to Clistomastus instead. Furthermore, as suggested in 

 the generic diagnosis above, Eisigella may prove to be congeneric vi^ith 

 Clistomastus. 



Distribution. — Notomastus (Clistomastus) tenuis is common in inter- 

 tidal zones of California from San Diego north to northern California 

 and Oregon. As Eisigella tenuis (Moore) it has been reported from 

 British Columbia in intertidal zones (Berkeley, 1929, p. 312). 



Notomastus (Clistomastus) luridus Verrill 

 Plate 49, Figs. 1-5 



Notomastus luridus Verrill, 1873, p. 610; Hartman, 1942, pp. 68-69. 



Material examined. — Barnstable, Massachusetts, August 30, 1875 

 (4 specimens from Verrill's collection at Yale University). 



Total length exceeds 80 mm (preserved) but none of the individuals 

 is entire. The prostomium is depressed, approximately triangular, about 

 as long as wide or slightly longer ; it has a slenderer anterior prolongation 

 corresponding to a palpode ; there are no visible eyespots ; the nuchal slits 

 occupy the usual position at the posterior margin. The proboscis, everted 

 more or less completely in 3 individuals, is sacklike, coarsely papillated on 

 its proximal portion but smooth and glistening distally; separation be- 

 tween the 2 regions is abrupt. When the proboscis is completely everted 

 the papillar region is hardly visible. 



The entire thoracic region is areolated but most conspicuously in the 

 first 6 segments and decreasingly thereafter. The abdominal region is 

 smooth except for transverse and oblique folds and wrinkles. Separation 

 between thorax and abdomen is more or less distinct because of the 

 change in parapodial parts from setae to hooks and because the body 

 tends to be abruptly wider in the abdomen than in the last thoracic seg- 

 ment. Most of the thoracic length is marked by a broad, shallow ventral 

 groove and lesser furrows at the sides between the notopodial and neuro- 

 podial parts. 



The first segment or peristomium is apodous and achaetous ; it is entire 

 or weakly biannulate on its ventral side ; its length is about that of the 

 next segment. The second, or first setigerous, segment is wider and 

 provided with an inconspicuous notopodial fascicle and a small lateral 

 organ on either side; these parts may be more or less withdrawn so as to 

 be hardly visible. The second setigerous segment is similar but the noto- 

 podium is slightly larger and a minute neuropodial fascicle can be dis- 

 tinguished. By the third setigerous segment the setal fascicles are still 



