COE: NEMERTEANS OF WEST AND NORTHWEST COASTS. 171 



esophageal nerves being unusually large. Both dorso-median and 

 internal dorso-raedian nerve clearly marked and of remarkably 

 large size. 



Cerebral sense organs voluminous, bathed posteriorly in the 

 large lateral blood lacunae as usual. Cephalic slits of moderate 

 depth. 



Habitat. — Mather common in crevices of rocks and under stones 

 between tides, as well as in mud among tiinicates growing on piles 

 of wharves, San Pedro, California. Dredged in several localities off 

 San Pedro in 2-20 fms. 



A single specimen was collected by the Albatross at Santa Mar- 

 garita Island, Lower California. This 8])ecimen has remained 

 bluish black after standing many years in alcohol, but the transverse 

 markings have disappeared, although there are indications of the 

 exceedingly fine longitudinal lines on dorsal surface. Tip of snout 

 whitish, as is usual in preserved specimens. 



20. Lineus w^ilsoni Coe. 

 Harriman Alaska Expedition, 11, p. 195, PI. 16, figs. 10,11, 1904. 



PL 3, %. 37. 



This species occurs abundantly at several localities on the coast of 

 California and may be recognized by the follownng peculiarities: — 



Body only moderately slender, rounded anteriorly, flattened in 

 intestinal region, but with rounded lateral margins; head very long, 

 slender, somewhat narrower just back of brain but not distinctly 

 marked off from body; cephalic furrows remarkably long ; mouth 

 large, situated far behind tip of snout and immediately behind brain ; 

 proboscis pore subterminal, near ventral margin of terminal white 

 border; proboscis slender, color very pale, with a tinge of yellow ; 

 proboscis sheath extends very nearly to the posterior extremity of 

 the body; intestinal region commonly much wrinkled and with 

 numerous constrictions; posterior extremity not very slender. 



Ocelli wanting. 

 • Body fragile, often constricted at the white rings described below, 

 and it is through these rings that spontaneous fission usually takes 

 place. Position of first rupture is usually through third white ring, 

 while the rings in front and behind remain intact. 



