THE GENERA OF NEMERTEANS. 215 



15. Cerebratulus dohrnii u. sp. 



To this species I refer several specimens from the bay 

 of Naples of no very considerable size but very gracefully 

 coloured. The four margins of the cephalic fissures are 

 marked off by thin brown streaks. Another brown streak 

 along the middle of the back is more sharply defined on 

 the head than farther backward. The ground-colour seems 

 to be pale yellowish ; to the right and left of the median 

 dorsal line there are two white longitudinal bands which 

 in their turn are bordered by two light brown ones occu- 

 pying the body margins. Near the tip of the snout there 

 are about three eyes on each side. Although there is a 

 certain resemblance between this species and C. bilineatus 

 Renier they cannot be confounded when examined in the 

 fresh state. The largest specimens measured when exten- 

 ded 4 cm. in length and l^/g i^^^' i^ width. 



16. Cerebratulus purpureas (Dalyell) Hubr. 

 Synon. Gordius purpureus spinifer Dalyell. 

 Micrura purpurea J. Muller. 

 Cerebratulus flavifrons Grube. 

 Micrura purpurea Mac Intosh. 



This species was not uncommon at Naples although I 

 never saw specimens of considerable size. The colour was 

 of a dark blackish purple; the white patch on the tip of 

 the snout seems to contain, when examined with the 

 microscope , two sets of pigment-grains. Eyes could not 

 be detected. The mouth is of moderate dimensions. There 

 is a thin caudal appendage on the posterior extremity of 

 the body. Dimensions of urticating elements in the proboscis 

 rather considerable (0.133 mm. with, 0.037 mm. without 

 the thread). 



17. Cerebratulus grubei. n. sp. 



Of this new species I was able to examine three spe- 



Notes from the Leyden Bluseum. 



