216 TÏÏE GENERA OF NEMERTEANS. 



cimens caught at different times and in different localities. 

 They resemble the foregoing species at first sight , espe- 

 cially by the colour. On closer inspection they proved to 

 be distinguished by the fact that the tip of the snout is 

 not white but black and that a very thin white transverse 

 ring makes its appearance immediately behind the tip of 

 the snout. Grube has already found this worm in the 

 Adriatic (Die Insel Lussin, Breslau , 18(34, page 96) 

 without however describing it as a distinct species. In 

 captivity the dark glossy colour of one of these animals 

 changed to a dirty light brown. In length they did not 

 exceed 14 mm. I was unable to detect a caudal appendage. 

 The mouth is moderate. 



18. Cerebratulus tristis n. sp. 



Two specimens were procured of this species which has 

 again by its dark purple coloration strong resemblance to 

 the two foregoing. The snout seems to be rather pointed , 

 more so than in the two latter species ; the coloration is 

 uniform all over the body; the cephalic fissures are long 

 and deep ; the mouth is exceedingly small. Urticating 

 elements were found in the proboscis , different in some 

 respects from those in the two foregoing species (the larger 

 ones only measured 0.011 mm. without thread). 



19. Cerebratulus geniculatus (delle Ch.) Quatrefages. 

 Synon. Notospermus drepanensis Huschke. 

 Notogymnus » Ehrenb. 



Meckelia annulata Grube. 

 Polia geniculata delle Chiaje. 

 (nee C. geniculatus Grube!) 



Of this species only one very young specimen was brought, 

 having the usual green colour; two others belonged to a 

 curious dark purple variety. The white rings round the 

 body were identical, the front one showed the characteristic 



Notes from the Leyden IVIuseura. 



