COE: NEMERTEANS OF WEST AND NORTHWEST COASTS. 193 



217) ; Mr. Abbott informs me that he has seen specimens which, 

 were collected at Kadiak, Alaska. 



82. Cerebratulus marginatus Renier. 

 Tavole per servire alle classificazione degli animali, Padova, 1807.. 



C angulatus ^Iclntosh, British Annelids, Pt. 1. Nemerteans, p. 195,. 



Ray Society, 1872-73. 

 C.fuscus Yerrill, Trans. Conn. Acad., 8, p. 438, 1892. 

 C. tnarginattis Burger, Fauna u. Flora von Neapel, p. 660, 1895. 



Text-tigs. 29, 30. 



The worms of this species may be recognized by their large, stout 

 bodies which are rounded anteriorlj', but flattened and with very 

 thin lateral margins in intestinal region; ocelli wanting; length 

 often 50 cm. to 1 meter; cephalic furrows large and deep, of mod- 

 erate length ; color grayish, greenish gray, slate color, pale brown- 

 ish or dark slaty brown, sometimes mottled on dorsal surface, but 

 usually paler beneath (sometimes very pale), and usually with very 

 pale or whitish lateral margins.^ The colors are well retained after 

 preservation. The worms are excellent swimmers and move rap- 

 idly in their burrow's. 



Habitat. — Characteristic individuals 50 cm. to a meter in length 

 are fairly common in mud in San Pedro Harbor, California, at low 

 water. Also dredged-in 3-5 fms. in channel, San Pedro. 



Some individuals are very pale, especially on the ventral surface, 

 while others which are decidedly dark on dorsal surface are pale 

 grayish ventrally. They apparently all belong to the one widely 

 distributed species, however, their internal anatomy agreeing with 

 that of C. marr/ hiatus from Naples. In many individuals the pale 

 color on the lateral margins is wanting. 



The species has previously be^n collected on the Pacific coast by 

 Griffin in Puget Sound ('98) and by myself at Sitka, Alaska (:01). 

 From this latter locality the w^orms were comparatively broader and 

 shorter than those from San Pedro or from Naples, and lived in 

 soft black mud. 



1 For colored drawings of living worms and description and figures of ana- 

 lomical peculiarities, see Biirger ('95). 



