NO. 13 coe: revision of the nemertean fauna 265 



Size. Up to 50-70 cm in length when mature and 5-12 mm in width. 



Color. Two intergrading color varieties may occur in the same 

 locality. The darker variety is rich purplish brown on both dorsal and 

 ventral surfaces, thickly sprinkled with minute white dots. More or less 

 conspicuous darker rings encircle the body at irregular intervals of 2-5 

 times the body diameter. Head white, speckled with fine red, orange, or 

 brown dots except near tip. The paler variety is rosy flesh color, thickly 

 speckled on dorsal surface with elongated reddish brown or purplish 

 dots ; with conspicuous purplish brown or black rings encircling the body; 

 ventral surface rosy flesh color; head white or slightly pink. Many devia- 

 tions from these two color patterns are found, particularly in younger 

 individuals, which may be reddish brown dorsally and grayish brown 

 ventrally with very inconspicuous rings. Occasionally the rings are 

 somewhat lighter than the intervening body color, in which case they 

 are bordered by darker rings. 



Ocelli. Absent. 



Habitat. Beneath stones and in hard clay near low-water mark and 

 below both on the open coast and in protected bays. 



Distribution. At present known only from Monterey Bay to San 

 Diego, California. 



Regeneration. Individuals of this species are very hardy and may live 

 for six months or more in the aquarium. Posterior regeneration occurs 

 readily at all levels in the intestinal region if connected with the head, 

 but anterior regeneration of body fragments has been limited to healing 

 without the formation of new head in all experiments up to the present 

 time. 



Genus LINEUS Sowerby 



Eight species of this genus are known to occur on the North Pacific 

 coast. Only 2 of these have been found in other parts of the world. 



Key to Species 



1. Tip of head not conspicuously different from body in color; 



body without distinct markings 2 



1. Tip of head of different color from that of body or with distinct 

 markings on body ^ 



2. Dusky or brownish green, dark brown, or reddish brown, com- 

 monly paler beneath ; a single row of 4 to 8 ocelli on each side 



of head - ^ 



