47 38 Proceedings of the Poyal Irish Academy. 



and position of the thick setae the two forms agree closely. In 1908 

 Mcintosh described Syllis Gunningliami, a species characterized by the 

 presence in each foot of two setae thicker than the rest. He did not 

 mention the two species already described, characterized by this peculiar 

 arrangement, and his description is very inadequate, but there seems no 

 reason to doubt that his species is identical with Elilersia simplex and 

 Syllis aesthetica. 



Habitat. — Clew Bay— A single specimen in Lithothamnion on the south 

 shore of Clare Island. 



Distribution. — Guernsey ; Dinard ; Madeira ; Canaries. 



Syllis (Ehlersia) ferrugina (Langerhans). 



1881. Ehlersia ferrugina. Langerhans, p. 104. 



A single specimen of this worm was found in Laminaria roots in Blacksod 

 Bay. It agrees with the description of Langerhans in the following points : — 

 (1) The number of joints in the tentacles and anterior cirri; (2) the dorsal 

 cirri alternate in length, and behind the first few segments they are smooth, 

 and not moniliform ; (3) the feet contain two kinds of setae, some having 

 short distinctly bidentate tips, others very long slender pointed tips. The 

 chief difference lies in the fact that the distinction between the two kinds of 

 setae in the anterior segments of Langerhans' specimens is not by any means 

 so marked as it is in segments further behind. In the Blacksod specimen the 

 distinction between the two kinds of setae is equally marked in all the feet. 

 The anterior cirri are also not so distinctly moniliform. It is at present 

 difficult to say whether these differences have specific value ; and until further 

 specimens are available, it seems better to regard the Blacksod form as a 

 variety of Langerhans' species, which has only been found in the Canaries. 



The present specimen, of which only the anterior 27 segments were 

 obtained, is a mature female and was found in March. On the 26th 

 segment there is a long bunch of swimming setae. There is no sign 

 that a bud is forming; and it is possible that the species reproduces 

 directly. If this is the case, it probably belongs to the genus Pionosyllis, 

 with which it has great affinities, and the smooth dorsal cirri lend strong 

 support to this opinion. The setae closely resemble those of Pionosyllis 

 lairielligera de St.- Joseph, from which species, however, it differs in the 

 absence of lamellate ventral cirri on the first setigerous segment, the struc- 

 ture of the spines, etc. It differs from Syllis comvta in having smooth 

 dorsal cirri and in the structure of the setae. It is possible that the 

 acephalous bud described under Syllis cormcta (p. 37) may belong to the 

 present species. 



