STHBNBLAIS ATLANTICA. 415 



when viewed laterally. They taper to a delicate extremity, and their rows of spines are 

 distinctly marked, though somewhat finer than in 8. boa. The inferior lobe is irregularly 

 conical, and has numerous papilla?, the largest near the spine, and just above the 

 inferior group of bristles. Moreover below the latter is a cluster of smaller papilla? fur- 

 nished with the secondary processes or warts at the tip. After a brief interval, a series of 

 globular warts occurs along the ventral border of the foot. The superior ventral bristles 

 (Plate XLI, fig. 25, in calcium chloride, and with the basal part of the terminal 

 appendage slightly folded) have comparatively strong shafts, with four or five rows of 

 spines at the dilated distal extremity, visible, however, only at its edge. The terminal 

 appendage as a rule consists of only two divisions, occasionally a more slender form at 

 the upper border having three. In those with two the terminal portion is only one 

 fifth the length of the basal. The claw at the tip is distinct and much curved, and the 

 secondary process projects at a slight angle, the point often touching the tip of the claw. 

 The basal joint is finely striated, as is likewise the dilated end of the shaft. As we 

 proceed downwards these bristles become less robust, and the shaft has a more distinct 

 dorsal curvature, but the terminal region of two divisions remains. Bach of the more 

 slender ventral groups, again, has three divisions in the terminal appendage (Plate XLI, 

 iig. 26, which represents one of the larger forms). The bristles throughout are tinted 

 of a light brownish hue. 



The ventral cirrus is subulate, and it reaches nearly as far as the fleshy part of the 

 foot (in spirit). The terminal region, which is elongate-ovoid, is marked from the 

 succeeding by a distinct shoulder, as if articulated. 



The absence of the head makes the generic relations of this species doubtful, but in 

 the meantime it may be placed under Sthenelais until a more complete example is 

 obtained. It is one of the many rare forms which the persevering explorations of 

 Dr. Gwyn Jeffreys in the Zetlandic seas brought within our knowledge. 



The 8. fuliginosa of Claparede l is an allied form, and the S. minor of Pruvot and 

 Racovitza 2 also approaches this species in regard to the structure of the papilla? and 

 the general character of the bristles, but differs in the presence of papilla? along the 

 ventral edge of the foot, and it has fewer papilla? on the scales than in the British form. 



3. Sthenelais atlantioa, Mcintosh, 1876. 



Specific Characters. — Head somewhat ovoid. Median tentacle subulate, and with 

 a terminal joint. A pair of eyes close together on each side,, near the base of the 

 tentacle. Palpi long, smooth, and tapering. Tentacular cirri show a terminal differen- 

 tiation, as in the median tentacle. Body as in S. zetlandica. Scales thin, rounded or 

 ovoid in front, reniform throughout the rest of the fragment, covered with sparsely 

 distributed but clavate cilia, and having a fringe of short clavate cilia, which are only 

 absent from a portion of the inner and adjoining anterior margin. They are longer and 

 more numerous than in S. zetlandica. Dorsal lobe of the feet bevelled from above 



1 < Ann. Chet. Naples/ p. 94, pi. iv, f. 2. 



2 ( Archives Zool. exper./ 1895,, p. 465. 



54 



