120 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 25 



papillae. Seen under high magnification they are distally globular, sub- 

 apically constricted and then spindle-shaped to the long, slender stalk. 

 They are longitudinally penetrated by a canal and have a distal pore. 

 There is an opaque mass of cells in the thickest region. These papillae 

 have the appearance of mucus-secreting cells. 



The functions of these 2 kinds of papillae appear to be totally unlike. 

 The large, balloonlike structures obviously explode outward when they 

 have attained their maximum size. This is demonstrated by the large 

 number of long filaments around the parapodial base, representing the 

 stalks of exploded balloons. It is here suggested that these papillae are 

 excretory in function, and thus may have their contact with the coelomic 

 space. This is all the more probable because this species, like other 

 members of the family, possesses a single nephridial pair, located at the 

 extreme anterior end of the body (Schlieper, 1927, p. 370). Most of the 

 surface of the body is thickly encrusted with sand, resembles an arenace- 

 ous armature, whereas the epithelium about the bases of notopodia is 

 thin-walled and protected from impact with the exterior by the investing 

 sheath. 



Flabelligera essenbergae departs from the genotype in lacking a mucoid 

 investing sheath, and neuropodial falcigers are incompletely, instead of 

 completely, articulated. It agrees in that the setae of the first segment 

 form a cephalic cage, and the neuropodia from the second segment are 

 falcigerous, somewhat composite. Epithelial papillae are of two distinctly 

 different kinds, and the prostomium is surrounded by a tentacular mem- 

 brane with many tentacles of a single kind. 



The species is known only from southern California in low, intertidal 

 zones. 



Genus Pherusa Oken, 1807 



Type P. plumosa (Miiller) 1776 



Pherusa papillata (Johnson) 1901 



Plate 24, figs. 1-7 



Trophonia papillata Johnson, 1901, p. 416, pi. 12, figs. 122, 123. 

 Stylarioides papillata Berkeley and Berkeley, 1952a, pp. 8-9, fig. 6. 



Collections. Many specimens come from Alaska south to California, 

 in intertidal to shelf depths. 



Length is about 50 mm; number of segments 72. The surface epithe- 

 lium is papillate, with individual papillae widely separated (PI. 24, fig. 

 1 ) . The anterior end of the body is broadest behind the cephalic cage. 



