262 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 2 



these specimens exceeded 1 m in length and were 12 to 18 mm in width 

 when contracted. This is evidently the most abundant as well as the most 

 conspicuous species of nemertean on the tropical Pacific coast. 



Habitat. In twisted tubes of tough mucus beneath stones and among 

 shells and corals along the shore near low-water mark and off shore at 

 depths up to 100 m or more. 



14. Baseodiscus platei Burger, 1896 



Eupolta platei Burger, 1896; Isler, 1901. 



This species, previously known only from the coasts of Chile and 

 Peru, was represented in the collections of the Allan Hancock Expedition 

 of 1935 by a single specimen about 23 cm long and 5 mm wide. It was 

 obtained from the shore of the lee side of Vieja Island, Independencia 

 Bay, Peru. 



15. Baseodiscus princeps (Coe), 1901 



Taeniosoma princeps Coe, 1901, 1904, 1905. 



Habitat. In mud and under stones in muddy situations between tides. 



Distribution. At present reported only from the coast of Alaska and 

 Puget Sound. 



16. Baseodiscus punnetti (Coe), 1904 



Taeniosoma punnetti Coe, 1904, 1905, 1905a; Joubin, 1905. 



Habitat. Common among red algae, corallines, corals, and other 

 growths from near low-water mark to depths of 100 m or more. 



Distribution. At present known only from Monterey Bay to San 

 Diego, California, and southward to the Gulf of California, Mexico. 



Family Lineidae 



Key to Genera 



1. Lateral edges of body folded back over dorsal surface to form 



longitudinal groove in dorsomedian line Diplopleura 



1. Dorsal surface without median longitudinal groove .... 2 



2. Without longitudinal cephalic grooves; caudal cirrus present 

 Zygeupolia 



2. With longitudinal cephalic grooves 3 



