coe: nemeeteans of west and northwest coasts. 203 



the lateral vessels of the esophageal region proper. Proboscis sheath 

 vessel passes through ventral wall of sheath shortly behind nephrid- 

 ial region. 



Nephridial tubules ramify among the esophageal lacunae in the 

 second and third fifths of the esophageal region. Its fiiiei- tubules 

 are gathered into a single large branching canal on each side, which 

 passes posteriorly to open on dorso-lateral surface of body by a 

 single efferent duct in about the middle of the esophageal region. 



Nervous system and sense organs. — Two or more pairs of large 

 neurochord cells lie on the internal faces of the ventral ganglia, as 

 in many other species of the genus. Cephalic nerves in front of 

 brain remarkably well developed, although there are no ocelli. 

 Cephalic furrows remarkably deep, reaching inward nearly to the 

 brain. 



Habitat. — Collected in mud near low water at San Pedro Harbor, 

 California ; Dead Man's Island, San Pedro ; San Diego, near Point 

 Loma, California. Not common. 



A single specimen apparently belonging to this species was col- 

 lected by the Albatross near Santa Barbara Islands, Califoinia (Sta. 

 2840) in 28 fms., green mud. 



This is one of the most fragile species of nemertean found on 

 the coast, nearly all of the specimens becoming fragmented as soon 

 as collected. The worms swim actively when disturbed. 



40. Cerebratulus latus, sp. nov. 



PI. 4, Fig. 41. 



Body remarkably short and broad for genus, much flattened 

 throughout, with unusually tliin lateral margins ; very ranch broader 

 than C. marginatus., C. lacteus, or related forms ; broader also than 

 those species related to C. fuscus, and of different proportions, 

 being largest anteriorly and tapering gradually toward posterior 

 extremity (PI. 4, fig. 41). Resembles C. marginatus somewhat 

 closely in general color of body, but is far shorter, broader and more 

 flattened both in life and after preservation. 



Length varies enormously according to state of contraction of 

 body; large specimens measure about 30 cm. in length and 25 mm. 

 in width when moderately extended. One specimen which measures 

 after preservation 29 mm, in width is but 18 cm. in length. 



