47 56 Proceedings of the Royal Irish Academy. 



The head (PI. VI, fig. 13a) is oval, and bears two pairs of kidney-shaped 

 eyes. The median tentacle is jointed at the base, and on each side of it is a 

 short rounded lobe, the cephalic ctenidium. The palps are long and tapering, 

 about eight times as long as the median tentacle. 



The parapodia of the first segment (fig. 13b) project in front of the head. 

 On the dorsal side, near the base, is a small rounded lobe (a), the dorsal 

 ctenidium of the first foot. On the inner margin of the base of the first foot 

 is the lateral tentacle (b), broad at the base, and tapering to a point. The 

 setigerous lobe also bears long slender dorsal and ventral cirri (c, d). Between 

 these, on the outer side of the setae, is a delicate membrane (e), the buccal 

 ctenidium ("cuilleron cephalique" of Pruvot and Eacovitza). The setae are 

 grouped in two bundles, but there is only a single spine. They are simple, 

 slender, and serrate. There are no compound setae in the first foot. The 

 relations of these various structures are shown in fig. 13b, in which the first 

 foot is seen from the outer side. 



Behind the head.on the dorsal side, the two anterior segments are prominent 

 in the median region, and project laterally as a pair of short blunt papillae. 



The second pair of feet project laterally in front of the head. Some of the 

 ventral setae are very long and slender, and the terminal pieces have 7-9 

 joints. In the succeeding feet these setae gradually grow shorter, and in the 

 5th foot have the normal number of two or three joints. 



The dorsal simple setae are minutely bifid at the tip, a point which 

 Mcintosh overlooked. 



The ventral cirri on the second pair of feet are larger than those on the 

 following segments, and are nearer to the median line of the body. The 

 ventral surface of the body is thickly covered with small globular papillae, 

 except in the median line beneath the nerve-cords. 



This species is closely related to the S. minor of Pruvot and Eacovitza. 

 It differs in having papillae on the ventral surface, and short clavate cilia on 

 the margin of the elytra, those in S. minor being long and tapering. There is 

 also considerable difference in the size of the body, and the proportions of the 

 various structures comprising the anterior end. 



Habitat. — Clew Bay— Dredged in 18 fms. 



Distribution. — Off the Shetland Islands ; off Port Erin, Isle of Man. 



Sthenelais limicola Ehlers. 



1900. Sthenelais limicola. Mcintosh, p. 417. 



This species was not found between tide-marks, nor does it occur in 

 Blacksod Bay. It is characteristic of a sandy bottom in shallow water. 



