178 



Dr. Johnston on the Irish Annelides. 



lamina of the setigerous tubercle is oval and not more than 

 half the size it has in iV. renalis ; and the foliaceous appendage 

 to the ventral cirrus in the former is also proportionably small, 

 and of a roundish figure, without any additional lobular ap- 

 pendage. 



Nereis margaritacea, described in the ' Annals/ vol. iii. p. 

 294, is also nearly allied to this species, and is, I suspect, the 

 same as the Nereis podophylla of Savigny. It requires re-ex- 

 amination ; and I would remark, that as these species are 

 easily injured, and their appendages tear and fold up readily, 

 several feet ought to be examined before fixing on their true 

 shape and character. I had made several figures of the feet 

 of N. renalis before the one now given, which, I believe, ex- 

 hibits a correct outline of its ordinary conformation. 



8. N. longissima, jaws obsoletely serrated at the base, plain 

 towards the points; proboscis without prickles; upper branchial 

 lobe with a helmet-shaped crest, the setiferous tubercle with 

 large kidney-shaped lamellae, and a smaller one of the same 

 figure is appended to the base of the ventral cirrus ; superior 

 cirrus rather longer than its lobe. 



Fig. 9. 



Nereis longissima. 

 Hob. Coast of co. Down, Wm. Thompson, Esq. 



The specimen before me is of the extraordinary length of 

 two feet ! but as it has become very soft in the spirits, it 

 M'ould perhaps not much exceed 18 inches when alive. It is 

 of the thickness of a goose-quill, and of a pearl colour with 

 olivaceous feet, which are very large and flexile. Head di- 



