294 Prof. M'Intosli's Notes from the 



(1ivero;es from anything at present known in the Syllids — even 

 from tlie condition in tlie parasitic Syllis on the eel. 



Were the facial tuhercle present in P. minuta, then the 

 other characters of P. fuberculata might reasonably be con- 

 strued as those of a variety of the common form, viz., the 

 "absence of papillae on the tentacular cirri" (since some 

 occur at their base), the more numerous papillije on the feet 

 and the ventral surface, and the shorter papillae on the scales. 

 The occurrence of white pigments in the palps and scales is 

 a feature of the variety. No facial tubercle has been made 

 out in the common form, therefore Southern's si)ecies stands. 



The post-larval examples of Pelagobia lonyicirrata, (ireef, 

 procured in the Irish Sea *, present two stages — different 

 from those figured by Reibisch, but agreeing in general 

 structure. The younger has three bristled segments, the 

 large head (for at its posterior border it is equal to the 

 diameter of the body) is broadly shield-shaped, the nairower 

 border being anterior. Two eyes — antero-posteriorly elon- 

 gated — occur toward the posterior border and are widely 

 separated. A tentacle projects on each side of the anterior 

 margin. The second pair arise behind each eye, are subulate 

 in shape, and slant forward, A pale area in the centre of 

 the snout indicates the mouth, which is at the anterior 

 extremity, and a small ovoid area occurs in the lateral region 

 and probably indicates the nuchal organ, which is conspicu- 

 ous in GreeFs form. The head thus diifers from G reef's in 

 the antero-posteriorly elongated eyes and in the brevity 

 of the tentacles, but it has to be remembered that his form 

 is much more advanced. 



The body is nearly cylindrical, though the two terminal 

 segments are considerably narrower, and has three bristled 

 segments, the first feet being the shortest, a brief interval 

 separating them from the head. Each forms a simple blunt 

 cone standing at right angles to the body and furnished with 

 a series of delicate translucent bristles with articulated 

 terminal pieces like those of Phyllodocids. The second feet 

 are considerably larger, also stand nearly at right angles to 

 the body, ;ind their bristles are longer and stronger. The 

 third pair slope distinctly backward. Each foot except 

 the last has a small subulate dorsal cirrus, which projects 

 only a little beyond the tip of the setigerous lobe, and is 

 in contrast with the two long cirri of Greef's type. 



Behirul the third foot is a narrow segment with a slight 



* For these pxamplos I aiu indebted to Mr. Cliadwick of the Port 

 Eriu Marine Lahoralors . 



