17* 



Dr. Johnston Ofl thr Irish Aiuwiuh's. 



I have also scarcely a doubt of this being the Nereis mar- 

 garitacea of Leach (Supp. Encyl. Brit. i. p. 451. pi. 26.), but 

 Dr. Leach's character of the species is entirely generical ; and 

 Savigny and Milne-Ed wards and Audouin have particularly 



described a Nereis margaritacea, which is not the same with 

 the one before us, but more nearly related to N. viridis. 



Neither has this any relation to the Nereis margaritacea of 

 the ( Annals/ vol. iii. p. 294, which belongs to a different sec- 

 tion of the genus. 



4. A', bilineata. 



I have nothing to add to the character and description of 

 this species given in the c Annals/ iii. p. 295. It does not 

 occur in the Irish collection. 



5. N. DumerilU, post-occipital segment equal in length to 

 the second ; tentacular cirri 3 times longer than its breadth ; 

 jaws serrulated; branches of the mid and posterior feet widely 

 separate, the lobes papillary, divaricate ; superior cirrus pro- 

 jecting far beyond the apex of its lobes. Aud. and Edw. Litt. 



de la France, ii. p. 196. 



Fig. 5. 



Xereis DumerilU. 



