NO. 3 HARTMAN : POLYCHAETOUS ANNELIDS 323 



Family GtenodHlidae 



Genus GTENODRILUS Claparede 



Type G. serratus (Schmidt) 



Gtenodrilus serratus (Schmidt) 



Plate 27, Figs. 6, 7 



Fauvel, 1927, pp. 108-109, fig. 38; Monro, 1933, p. 265; Augener, 1936, 

 p. 350. 



Collections. — 1438-41 (8) ; San Francisco Bay, California (10). 



Minute, inconspicuous, only 2.5 to 6 mm long; number of segments 

 9 to 1 1 or a few more. The prostomium is a simple, bluntly conical lobe, 

 lacks appendages or eyespots, but is heavily ciliated. The first segment 

 lacks setae but has a band of cilia ventrally (pi. 27, fig. 6). Notopodia 

 and neuropodia are represented only by reduced setal fascicles, typically 

 2 to 4 in each bundle; they are simple, distally serrated (pi. 27, fig. 7). 



Color in life was noted for individuals from Point Richmond, San 

 Francisco Bay. The body is translucent, pale at either end, with a maroon 

 to purple cast over the middle half to two thirds of its length; the entire 

 surface is speckled with dark. Progression is a slow, creeping movement, 

 in either direction. Individuals have been recovered from clumps of 

 debris; no tube or burrow has been identified. 



The family with which this species is identified has sometimes been 

 regarded as a subfamily of the Cirratulidae (Fauvel, 1927, p. 107). It 

 is herein considered distinct because of the presence of unique characters, 

 notably the ciliation of prostomium and first segment, the reduced number 

 of body segments, inconspicuous parapodia, and simple setal fascicles. 



Reproduction by transverse fission, protandric hermaphroditism, and 

 internal gestation have been reported for individuals from Europe (see 

 Fauvel, 1927, p. 109). These interesting phenomena have not been in- 

 vestigated for specimens from the Western Hemisphere. 



Distribution. — Central and southern California; West Indies; 

 Europe. 



Family SabellaHidae 



The family Sabellariidae constitutes a comparatively small, distinct 

 group; affinities with other chaetopods are not easily discernible, but 

 present-day forms are probably nearest the Pectinariidae. The reef- 

 building habit is more or less strongly established. Species are typically 

 colonial, in some cases known to construct sandy reefs of great extent 

 (pi. 42, fig. 106) ; less often they are solitary, the sandy tubes attached 



