174 bulletin: museum of comparative zoology. 



through about half the length of the head, where it merges into the 

 narroAv dorsal stripe which continues throughout the bod}'. Most 

 individuals sliovv a faint reddish line extending from each cephalic 

 furrow backward along lateral margin of body (PI. 2, fig. 27). 

 Cephalic fuiTows often slightly paler, and rosy ; intestinal region 

 inclining toward an olive brown shade. Colors and markings of 

 body well retai>ied after preservation. 



Size. — Length commonly about 10-20 cm. ; width 2 mm. or 

 more. 



Ocelli apparently wanting. 



Proboscis with only two muscular layers, inner longitudinal mus- 

 cles being almost comi)letely wanting ; consequently the pair of 

 nerves appears to lie directly beneath the inner epithelial layer. 

 Proboscis attached posteriorly by a broad and powerful muscle to 

 dorsal wall of proboscis sheath at the boundary of esophageal and 

 intestinal regions. Back of this point cavity of sheath becomes 

 very small, and extends but a short distance into intestinal region. 



Blood lacuna in front of V)rain very extensive, completely sur- 

 rounding the walls of rhynchodaeum, except ventrally. 



Nephridlal system very short, limited to the second fifth of 

 esophageal region; likewise remarkable for the small number and 

 comparatively large size of its branches. A single main nephridial 

 canal on each side, situated in the connective tissue just above lateral 

 blood lacuna, extends backward without bianches for a distance 

 fully equal to that occupied by its anterior branching portion ; the 

 efferent duct then passes directly outward from the posterior end of 

 the longitudinal canal and opens externally immediately above 

 lateral margin. 



Cephalic glands remarkably voluminous, reaching deep into 

 tissues of head, and extending posteriorly almost to anterior end of 

 brain region. 



Cutis glands extend inward entirely through the outer longitu- 

 dinal muscular layer, except toward the lateral margins of body. 

 Pigment of body situated mainly just outside circular nniscles. 



Habitat. — Dredged in 30 fms., off San Pedro, California, the 

 worms inhabiting strong, parchment-like tubes among broken shells. 

 Found also in 20 fms. in ^lonterey Bay, California (J. F. Abbott). 

 Not common. 



