422 STHENELAIS JEFFREYS!!. 



shafts are stronger, and with less delicate and less numerously jointed tips. Some have 

 one or two rows of spines at the distal end of the shaft, and a bifid tip, with a claw and 

 secondary process, the joints ranging from one to three, the latter kind being inferior. 

 The delicate inferior group (below the lobule) have also one or two rows of spines on 

 the distal end of the shaft, a long tapering terminal process of six or seven joints, and a 

 bifid tip. The subulate ventral cirrus extends nearly to the tip of the fleshy part of the 

 foot. 



Synonym. 



1876. Sthenelais Jeffreysii, Mcintosh. Trans. Zool. Soc, vol. ix, p. 406, pi. lxxii, f. 18, 19; pi. lxxiii, 



f. 1 and 2. 



Habitat. — Dredged in the Atlantic off the west coast of Ireland (Galway) in lat. 

 53° 16' X., and long. 12° 42' W., in 165 fathoms, Station 9, < Porcupine,' 1869. 



Head (Plate XXIX, fig. 4) broadly ovate, with a median ridge running forward to the 

 base of the tentacle, which is a tapering organ, longer and thicker than that of S. limi- 

 cola. The lateral regions of the head form smooth ovoid lobes. No eyes are visible in 

 the preparation. The first foot carries the following organs : dorsally the lateral 

 tentacle (of some length) inside the bristle-bundle, and externally the dorsal cirrus, both 

 reaching in spirit beyond the tips of the bristles. Just beneath the former is the 

 lamellar process, while ventrally is the shorter and more slender ventral cirrus. The 

 long, smooth, tapering palpus with the sheath-like lamella at the base — superiorly and 

 internally — arises from the ventral aspect of the process. The structure of the parts 

 thus diverges from that in S. limicola, and leans to those with more numerous processes, 

 as for instance S. boa. 



Body narrow, probably about two inches long, and with numerous segments. 

 Scales (Plate XXXIV, fig. 13). — First pair rounded, the rest more or less reniform, 

 and all smooth, translucent, and devoid of pigment in the preparations. On the external 

 border are long, slightly tapered papillae, perhaps more numerous in the anterior scales, 

 becoming fewer as we proceed backwards, and finally in the posterior scales disappearing 

 altogether, — that is to say, if the first form agrees with the closely allied Norwegian 

 species. The number of cilia (Plate XLII, fig. 5) on the external border thus varies, ten 

 being a usual number anteriorly, and their great length is in contrast with those of S. 

 boa (Plate XXXIII, fig. 16). In the latter the edge of the scale has been doubled, so 

 as to show (somewhat out of focus) the smaller papillse on the surface. 



Feet (Plate XXXI, fig. 7). — Superiorly is the long branchial process, and three 

 ciliated pads (ctenidia) along the dorsal edge. The dorsal lobe is somewhat clavate, 

 bevelled at the tip superiorly, and bears three papilla?, one at its tip, one projecting 

 from the upper bevelled region, and another near it — the two latter springing from the 

 anterior aspect of the foot, and a tuft of the usual slender bristles with fine and rather 

 closely set rows of spines. The ventral division is somewhat conical at the tip, and has 

 one or two mammillary papillse at the apex to which the spine goes, and one on each of 

 the lobes — superiorly and inferiorly. These are generally constricted at the base. The 

 superior ventral bristles are somewhat slender, have four rows of spines on the enlarged 



