216 



bulletin: museum of comparative zoology. 



Habitat. — Common on piles of wharves at Monterey Bay, San 

 Pedro, and San Diego, California. Common also on the coast of 

 New England. 



The worms belonging to this species are exceedingly active and 

 restless, as described by Verrill ('92). Sexual products were found 

 to be nearly mature in August, in California. Matui-e ova are gieen- 

 ish in color. 



A single specimen, 25 mm. in length and "1^ mm. wide, which 

 agrees with the above in all essential anatomical structures, was 

 dredged off Coronado Beach, California, in 10 fms. Color after pres- 

 ervation dark grayish brown, but after being cleared in cedar oil 

 assumed a purplish color with a tinge of green. Ocelli, internal 

 structure, and proboscis armature are as in that species, and the pro- 

 boscis is provided with 10 nerves only as in many of the individuals 

 from New England. 



The closely related species found in Alaska {Z. thalassina) differs 

 from the above in number of nerves of j^roboscis and character of its 

 armature, as stated on p. 213. 



46. Zygonemertes albida Coe. 



Fig. 36. — Zygonemertes 

 albida. Stylet appara- 

 tus of proboscis. 



Proc. Wash. Acad. Sci., 3, p. 31, PI. 3, %. 2 ; 



PI. 8, fig. 5, 1901 ; Harriman Alaska 



Expedition, 11, p. 31, 1904. 



PL 24, figs. 182, 183; Text-fig. 86. 



This is a small, moderately slender species, 

 very active in habits. Sexually mature indi- 

 viduals were not more than 25 vanx. in length. 

 The color of these minute -worms is white, 

 with a tinge of yellow both above and below. 

 Ocelli very numerous, being scattered irregu- 

 larly on the head in front of the brain and 

 extending l)ackward as a single row on each 

 side along the lateral nerves for about two 

 fifths the length of the esophageal region 

 (PL 24, fig. 182). Central stylet of probos- 

 cis rather slender, basis elongated, sharply 

 truncated posteriorly (Text-fig. 36, PL 24, fig. 



