160 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



The transverse black spot on dorsal surface of tip of snout is per- 

 fectly distinct, the dorsal surface of body is pale brownish, while 

 the ventral surface has lost all trace of original coloration. 



The worms are very hardy and tenacious of life, being able to 

 live for a day or more among damp seaweeds. They may be kept 

 for a long time in captivity, and do not break up when roughly 

 handled. They are easily preserved without rupture, or without 

 excessive contraction if killed slowly. Natural colors are well 

 retained in formalin. 



Zygeupolia C. B. Thompson. 

 Zool. Anz., 23, p. 151, 1900. 



Body moderately slender ; head very long and acutely pointed,, 

 without lateral furrows ; cerel)ral sense organs well developed, con- 

 nected mth exterior by ciliated duct opening into shallow pit on 

 lateral margin of head ; ocelli wanting ; caudal cirrus conspicuous, 

 with large central l)lood space connected both with lateral and with 

 dorso-median vessels. Proboscis sheath extends throughout length 

 of body ; proboscis with but two muscular layers — outer longitudi- 

 nal and inner circular ; proboscis without retractor muscle. 



As stated by Miss Thompson (:02, p. 731) this genus undoubt- 

 edly belongs to the family Lineidae. The absence of lateral 

 cephalic furrows is not of very fundamental imj)ortance, for, as 

 stated on p. 57, different species of the same genus sometimes show 

 nearly all gradations between deep horizontal furrows and merely 

 slight lateral grooves or pits into which the canals from the cerebral 

 sense organs open. Cerebratulus coloratus Burger is an example of 

 such a form in which lateral horizontal furrows are practically want- 

 ing, while other members of this same genus have the most highly 

 developed furrows of any nemerteans. 



14. Zygeupolia littoralis C. B. Thompson. 



Zool. Anz., 23, p. 151-158, 1900; Proc. Acad. Nat. Sci. Phil., 1901, 



p. 657-739, PI. 40-44, 1902. 



Text-figs. 4, 18. 

 This very interesting species which has been so carefully studied 



