490 GLYCERA ALBA. 



the dorsal lobe, and the dorsal process or cirrus moves inward on the foot. All the long 

 lobes of the foot are now more pointed, this condition being especially marked in the 

 ventral lobe. The lower posterior lobe remains short and rounded. 



The branchiae seem to be readily thrown off in the preparations, and probably even 

 m life, as many in certain examples appear to be in process of reproduction. About ten 

 or twelve segments anteriorly and posteriorly are devoid of them. 



In life the dorsum of the foot appears to be specially branchial in function, the 

 interior being boldly ciliated, and the rich crimson perivisceral corpuscles rush to and fro 

 and revolve rapidly. In the sickly animal the corpuscles tint the dorsum of the foot as 

 well as the superior process. Long motionless processes resembling cilia occur on the 

 slight convexity within the ventral process. 



In a form from the south-west of Ireland (1885— log 29, 40 fms.) the lower 

 posterior papilla or lobe is longer than usual, and considerable variation exists in the 

 length of the processes. Thus all the lobes as well as the ventral cirrus are long and 

 pointed in an example dredged by the ' Porcupine ' off Cape Sagres (Plate LXXVI, 

 fig. 3 e). 



In all probability the Olycera unicornis of Savigny 1 is this species. Its locality was 

 unknown. He did not distinguish the branchia from the other processes of the feet. 



Keferstein 3 described a new species from St. Vaast-la-Hougue which he termed 

 Glycera convoluta. So far as can be determined by a perusal of the literature of the 

 subject and of specimens having this name, it would appear to be only a variety of the 

 widely distributed Glycera alba, H. Rathke, and in this Bidenkap 3 and De St. Joseph 4 

 now agree. Such also was the opinion of Grube, though he indicated certain differences 

 in the feet and in the papillae of the proboscis. 



It is doubtful if the Rhynchobolus convolutus of Claparede 5 (Glycera convoluta, Kef.) 

 is other than a variety of G. alba, though he gives fourteen spurious segments to the 

 prostomium, and he places the branchia further from the tip of the foot than Keferstein. 



Willemoes-Suhm (1873) gives a brief account of the sense-organs (nuchal organs) of 

 this species from Faroe. It is a protrusible structure on the dorsum of the segment on 

 each side in front of the first bristles. 



Levinsen (1883) would be inclined to place Malmgren's Glycera Goesi under this 

 form. 



Wiren 6 ' refers to the composition of the perivisceral fluid of this species and the 

 presence of haemoglobin. 



This may be the species referred to by Miss Newbigging from the Clyde at Millport. 7 



1 ' Syst. des Ann el./ p. 37. 



3 ' Zeitschr. f . wiss. Zool./ xii, p. 106, Taf. ix, figs. 28 and 29. 



3 < Christ. Yidensk. Selsk. Forhandl./ 1894, p. 77. 



4 ' Ann. Sc. nat./ 8 e ser., t. v, p. 345. 



5 ' Annel. Nap./ p. 186, pi. xvi, fig. 3, 1868. 



6 "Oni blodet och blodomloppet hos Glycera alba, H.R./' f Biol. Foren. Forhandl./ Stockholm, 

 Bd. ii, p. 31, 1889. 



Communic. Millport Mar. Lab./ i, 1900, p. 4. 



7 t 



