Clare Island Survey — Archiannelida and Pohjchaeta. 47 87 



Marphysa fallax Marion and Bobretzky. • 



PI. VIII, fig. 20. 



1875. Marphysa foliate. Marion and Bobretzky, p. 14. 1888. M.f. 



de Saint-Joseph, p. 205. 



A single specimen of this species was found under a stone, on Barranagh, 

 Blacksod Bay. It has been found by Marion and Bobretzky at Marseilles, 

 and by de Saint- Joseph at Dinard. The specimen was 31 mm. long, con- 

 sisting of 100 setigerous segments. The distinctive colouring was not 

 retained by the preserved specimen. The head is well represented by the 

 figure of Marion and Bobretzky (torn, cit., fig. Ia), but in the Irish specimen 

 the anterior margin of the head is more deeply indented. 



The feet gradually increase in size up to the 14th segment, where the 

 first branchial filament appears. The feet differ in certain definite points 

 from the description of Marion and Bobretzky. There is a single branchial 

 filament on 13 feet (14-26) ; the succeeding 34 feet (27-60) have two filaments. 

 Then follow 20 feet (61-80) with again a single filament, and finally the 

 posterior 20 feet are without branchiae. According to Marion and Bobretzky 

 there are only 3 or 4 anterior segments with a single filament, 19 with 

 two filaments, and then 10 with a single filament. In de Saint-Joseph's 

 specimen, which was a young form, no branchia had more than a single 

 filament. Marion and Bobretzky found that the branchial filaments only 

 slightly exceeded the dorsal cirrus in length, whereas, in the mid-region of the 

 Irish specimen, they are 4-5 times as long. There are three spines in the 

 ventral division of the foot, and one slender spine in the dorsal division. 



The compound setae with the bifid tips were found only in a few of the 

 anterior feet, and never more than two in each foot. 



Neither Marion and Bobretzky nor de Saint- Joseph say anything about 

 the anal segment of this species. In the Irish specimen this segment is 

 funnel-shaped (fig. 20) with lobed border, and has four pairs of cirri of different 

 sizes on its ventral margin. Further observations on this species will probably 

 clear up any discrepancies between this specimen and those of the previous 

 observers. 



Habitat. — Blacksod Bay — Under a stone on the shore of Barranagh. 



Distribution. — Dinard ; Marseilles. 



Marphysa sanguinea (Montagu). 



1910, Marphysa sartguinea. Mcintosh, p. 442. . : 

 .. A single specimen was; found. on the shore in BaUyriakiil Harbour. 

 Habitat. — Ballynakill HaebouE— On the shore. " 



