STHENELAIS JEFFKEYSIL 421 



in the number of papillae. In the inferior division the flattened lobe becomes a much 

 smaller rounded process above the spine, and has a large papilla attached to it superiorly. 

 The simple spinous bristles of this lobe disappear, and a few bearing three rows of spines 

 on the end of the shaft and a terminal division of three segments occur, the tip being- 

 simple. Others show four articulations. Above and below the spine are stouter bristles 

 having tips of a single joint, or of two or three, strongly bifid, and this condition holds 

 in front in certain Norwegian examples. 



The slender inferior series show very delicate tips, with about four joints and simple 

 hair-like extremities. The lobe beneath the spine in these feet does not diminish so 

 much in proportion as that above it, 



Reproduction. — Specimens tossed on the beach at St. Andrews in February had 

 numerous large ova, so that the reproductive period would seem to be early spring, 



Habits. — It appears to be a dweller in sand, and is somewhat sluggish in confinement. 

 The finest specimens in my collection came from St. Andrews, but those from Shetland 

 and Polperro are also of considerable size. 



Dalyell's A.phroclita arcta may be this species, or an allied form. Unfortunately no 

 distinctive feature is given. 



The Sthenelais leiolepis of Claparede, from Naples, approaches this species in the 

 form of the scale, as pointed out by the Swiss author. It is distinguished from it by the 

 occurrence of only one ciliated mammilla below the branchia. Pruvot and Eacovitza unite 

 them, and consider the distinctions rested on imperfect observations. 



5. Sthenelais Jeffreysii, Mcintosh, 1876. 



Specific Characters. — Head broadly ovate, with a median riclge running forward to 

 the base of the tentacle, which is longer and thicker than in S. limicola. Lateral regions 

 of the head form smooth ovoid lobes. No eyes in the preparation. The massive first 

 foot carries dorsally the lateral tentacle internal to the bristle-bundle, and the dorsal 

 cirrus externally, both extending 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 its sheath-like lamella at the base — 

 superiorly and internally — arises below the process. Body narrow, probably about two 

 inches in length, and with numerous segments. Scales smooth, translucent, and devoid 

 of pigment in the preparation ; first pair probably rounded, rest reniform. On the 

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

 scales, and they may disappear posteriorly. The foot has a branchial process, and three 

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

 bevelled at the tip, with three long papillae, and a tuft of tapering bristles bearing fine and 

 rather closely set rows of spines. The ventral division has a conical tip, with one or two 

 papillae at the apex, and one on each of the lobes. The upper ventral bristles have four 

 rows of spines on the distal end of the shaft, and a most delicate tapering terminal 

 process of twelve to fifteen articulations ending in a hair-like tip. Below the spine the 



