Clare Island Survey — Archiannelida and Polychaeta. 47 71 



ventral side. The feet and setae agree closely with Mcintosh's description 

 and figures, except that the second tooth on the tip of the shaft of the setae 

 is somewhat larger. 



Habitat. — Ballynakill Harbour — Dredged in 6-8 fathoms. 



Distribution. — Berehaven ; St. Andrews ; off Cape Sagres. 



Mystides (Protomystides) bidentata Langerhans. 

 PL VIII, figs. 17 A, B. 



1879 a. M. h. Langerhans, p. 310. 1888. M. b. de St.- Joseph, p. 308. 



A large number of specimens of this species were obtained in a haul of the 

 dredge in 24 fathoms in Clew Bay. They are greenish-yellow in colour, and 

 vary in length from 5-25 mm. On the ventral surface there is a dark-brown 

 pigment spot at the base of each foot. 



The head in preserved specimens is not so long and slender as de St.- 

 Joseph figures it. The tentacular cirri agree in arrangement with the figures 

 of Langerhans and de St.-Joseph, but in a few of the specimens they are 

 much longer. They have their greatest thickness at the base, and taper to 

 a point. The segments are well marked. The feet are provided with ovate 

 cirri, and the setigerous region is bifid, with about 8-10 setae. The ventral 

 setae are considerably thicker than the median setae, and the terminal blades 

 are much shorter (PL VIII, fig. 17 b). The dorsal setae are intermediate in 

 these respects. The setae are slightly curved and the dilated and bevelled tip of 

 the shaft bears two unequal claws, between which the terminal blade is fixed. 

 In addition to the two large claws, the tip of the shaft bears a number of 

 small spines. The terminal blade, of very variable length, tapers to a line 

 point, and is minutely serrate. The anal segment bears two slender cirri, 

 swollen at the base, and tapering to a point. Between them is a long slender 

 papilla. 



A mature male, provided with swimming setae, was dredged in 16 

 fathoms near Bofin Harbour in June, 1899. It was 23 mm. long, and had 

 190 segments. The body was filled with sperm, giving it a creamy brown 

 colour. The swimming setae are present on segments 40-157. Pig. 17 a 

 represents a foot from the middle of the body. De St.-Joseph dredged a 

 mature female at Dinard (1906, p. 227, foot-note) filled with green eggs, and 

 with slender swimming setae, beginning on the 66th segment. 



The generic distinctions in the family Phyllodocidae seem to me to be 

 somewhat arbitrary. In the present species, the ventral cirri of the second 

 segment are much above the normal size, and should be considered as 

 tentacular cirri. The latter structures will then have the arrangement 

 characteristic of the genus Phyllodoce, sub-genus Carobia. 



