56 Prof. M'Tntosli's Notes from the 



or less complete. In this the stout filament tapered distally, 

 the pinnse diminishing to small papillae, then a free process 

 from the tip of which a very long thread-like appendage 

 projected. If such is the normal condition in this curious 

 species, it is little wonder no others were perfect. The body 

 is about 1^ inches long, the branchial region being fully 

 \ inch more, and the segments are about fifty-eight. It is 

 flattened both dorsally and ventrally with the exception of 

 the anterior region of the scutes, a median groove running 

 the entire length dorsally and from behind the anterior 

 region ventrally. The tail especially is flattened and oar- 

 or spatula-shaped, the diminution at the tip being slight. 

 The anal slit is ventral, and on each side is a rounded 

 papilla (or cirrus) on a short stalk. The flattening through- 

 out the greater part of the body is characteristic ; and the 

 constriction in front of the spatulate tail is well-marked. 

 The anterior bristles follow the normal condition in the 

 genus, viz., a longer and a shorter series. The longer bristles 

 (PI. I. fig. 3) have cylindrical golden shafts with a marked 

 slant backward, after the commencement of the narrow 

 wings and a finely tapered tip. The shorter forms (PI. I. 

 fig. 4) have a broad paddle-shaped tip with a distal median 

 process — the continuation of the tapering shaft. Whilst 

 the latter presents no striae, the broad Avings which form 

 the paddle are striated longitudinally. Posteriorly the tips 

 of the longer bristles become more and more elongated and 

 the wings narrower, until toward the end of the tail they 

 are invisible on the hair-like extremities of the attenuated 

 bristles. The shorter forms, again, undergo a similar 

 change, the tips elongating and the wings becoming nar- 

 rower, though they alM'ays retain a much broader and 

 shorter tip than the foregoing. Indeed, in the caudal 

 region the bristles increase much in strength while dimin- 

 ishing in number, and a tendency to assume the knife-blade 

 outline is noticeable, a constriction of the shaft occurring 

 below the tip. These stout caudal bristles evidently have 

 special functions. 



The anterior hooks (PI. I. fig. 6) are remarkable for their 

 high crowns and for the great proportional lengtii of the 

 base, which in this species appears to be of a tougher 

 nature — in fact, they simulate the condition in such forms 

 as Pista, Terebellides, and Chone. The main fang makes a 

 small angle with the neck, and its base is differentiated 

 almost to the posterior outline of the hook, whilst above it 

 the elevated and bluntly conical crown shows in lateral view 

 five distinct teeth and several indistinct upper ones. The 



