COE: NEMERTEANS OF WEST AND NORTHWEST COASTS. 199 



sand and mud off central California (Sta. 3138, 36° 55' N. Lat., 1'1'1° 

 02' W. Long.) at a depth of 19 fms. The known range of this 

 species is therefore from southern California to Sitka, Alaska, and 

 its known range in depth is from h)w water to 53 fms. The worms 

 are excellent swimmers and are very i-estless in confinement. 



37. Cerebratulus longiceps Coe. 



Proc. Wash. Acad. Sci., 3, p. 77, Pi. 5, figs. 4-7, 1901 ; Harriman 

 Alaska Expedition, 11, p. 77, 1904. 



Body much flattened throughout; head and anterior portions 

 of body remarkably slender and much flattened ; head very long, 

 acutely pointed ; cephalic furrows remarkably long, wide and dee)) ; 

 mouth situated opposite posterior ends of cephalic furrows ; ocelli 

 apparently wanting. Body very fragile, usually much broken when 

 killed. 



Length 15 to 30 cm.; wi<lth in intestinal region 3-5 mm. 



Proboscis slender and colorless ; with three muscular layers and 

 the usual muscular crosses. 



Color brownish black or purplish throughout body, except for 

 slight grayish tinge on ventral surface; paler on tip of snout and on 

 borders of cephalic furrows. 



Nephridial system presents several striking peculiarities. It 

 extends through whole length of esophageal region and possesses 

 upward of sixti/ efferent ducts on each side. Immediately behind 

 the mouth are one or two pairs of nephridial tubules which 

 are quite independent of the rest of the system, each consisting of a 

 coil of fine canals lying on the dorsal side of the lateral blood lacuna 

 and projecting freely into its cavity. From each of these tubules 

 an efferent duct leads to dorsal surface of body. Posterior to these 

 isolated nephridia is a richly branched system continuous throughout 

 the whole length of the esophageal region. The finer branches 

 project into the cavities of the blood lacunae and encroach greatly 

 upon their area. The very numerous efferent ducts vary greatly in 

 size, some being several times as large as others. They are disposed 

 with great irregularity, two or three ducts sometimes appearing on 

 the same side in a single section, some being situated much nearer 

 the dorso-median line tlian the others. The anterior, isolated 



