STHBNBLAIS LIMICOLA. 417 



(ctenidia) occur on the dorsum, but the specimen is not in a condition to speak decisively. 

 The ventral cirrus is slender and rather short, the tip being shorter than the fleshy 

 part of the foot. The preparations would seem to indicate a joint at the tip. In a 

 former note it was mentioned that some minute warts appear along the ventral margin of 

 the foot, but the preparations are now doubtful on this point. 



The species comes near 8. zetlanclica, yet the points indicated seem to warrant 

 separation. Both species approach Olaparede's S. ctenolepis from the Mediterranean, 1 

 but yet are sufficiently distinct. 



4. Sthenelais limicola, Ehlers, 1864. 



Specific Characters. — Head ovoid with the long diameter transverse, and median 

 space bounded by a brownish crescentic line on each side. Anterior and larger pair of 

 eyes often scarcely visible from the dorsum, being situated under the lateral processes 

 at the base (ceratophore) of the median tentacle, and looking forward. Posterior pair of 

 considerable size, a little behind the base of the median tentacle. Both occasionally show 

 a pale speck in the centre, as if from a lens. Base of the median tentacle (ceratophore) 

 somewhat conical (in spirit) ; tentacle of moderate length, the filiform tip being slightly 

 enlarged, and with a trace of an articulation. On each side of the base is a flattened 

 spathulate process (ctenidium). First foot fused ventrally with the base of the long, 

 tapering, smooth palpus, with a small sheath-like process (ctenidium) at its base 

 internally; then come a filiform ventral tentacular cirrus and a much larger dorsal 

 cirrus, and internally to the ventral cirrus a broad scimitar-shaped process (ctenidium). 

 Above and behind the latter is the small terminal region of the lateral tentacle. 

 Proboscis trumpet-shaped in extension, with eleven conical papillas dorsally and ventrally. 

 The teeth appear to bite as in 8. boa. Body elongate, more than two inches long, and 

 having about 128 segments. It tapers to a slender tail with two styles. Segmental 

 eminence opposite each foot ; no papilla. Scales smooth, translucent, brownish, covering 

 the back. First pair rounded, each with short clavate cilia along its outer border, and 

 a few larger digit-like forms at its anterior and outer margin. The others are more or 

 less reniform, the outer margin thin, folded, and having irregular processes — simple, bifid, 

 or irregularly divided. In the posterior scales the outer margin is bilobed, and in those 

 near the caudal region a belt of large round vesicles occurs in the hypoderm in front 

 of the scar: a touch of brown is present in some scales. Feet with branchial process, 

 and three ciliated pads (ctenidia) dorsally. The dorsal lobe is prominent, somewhat 

 clavate in outline, and has anteriorly four or hve long papillaa (stylodes) from its upper 

 end, the spine projecting inferiorly. The bristles are long, slender, tapering, and finely 

 spinous. The ventral lobe is shorter and broader, somewhat conical at the tip, and 

 bears one leaf-like lobe above the spine, and a smaller lobule at the ventral edge, a long 

 papilla (stylode ?) likewise being attached to the former region. Upper bristles like 

 those in S. boa, with simple spinous tips, only more slender. The next have slender 

 shafts with long tapering tips of twelve or more segments, and minutely bifid. A 



1 ' Ann. Chet. Naples/ 88. 



