BY WILLIAM A. HASWELL. 333 



with two sets of setae, except in a few of the most anterior seg- 

 ments ; seta3 of both sets few in number ; those of the dorsal set 

 very fine, tapering ; those of the ventral set stouter, curved at the 

 ends. The seta? of the most anterior segments greatly prolonged, 

 forming a complete circlet directed forwards. The praestomium 

 with two pairs of eyes. Branchiae numerous, cylindrical, borne on 

 a pair of club-shaped prolongations of the praestomium. 

 Tentacles very long,* cylindrical, smooth, with a ventral longi- 

 tudinal groove. Peristomium produced, capable of being retracted 

 together with the praestomium (and the branchiae?) within a 

 sheath formed for it by the following segment. Papillae very 

 numerous, not arranged in rows, and equally developed on all 

 sides of the body ; some of those around the bases of the anterior 

 large seta? extremely produced. 



Ill — Description op two species of Stylarioides*. 



Stylarioides cinctus (Plate xxvi. fig. 4). 



The total length (exclusive of the setae) is 2 -2 5 cm. The longest 

 seta? of the anterior segments are nearly one centimetre in length. 

 The greatest breadth of the body is 3 mm. The total number of 

 segments is 48. 



The praestomium (fig. 5) is produced forwards Jon the dorsal 

 side into a curved lamina, on the anterior edge of which are 

 situated the branchiae. Of the latter there are ten, all cylindrical 

 filaments, the central pair considerably longer than the others 

 and not very much shorter than the tentacles : each branchia 

 presents a pair of longitudinal crimson bands. The antennae are 

 dorso- ventral ly compressed, transversely corrugated, with a deep 

 longitudinal ventral groove, about -the length of the first four 

 segments. 



The body is cylindrical, somewhat dilated in the anterior portion, 

 narrowing suddenly behind the twentieth segment ; the posterior, 

 narrow part tapering posteriorly. In a second specimen the ten 



* A3 defined by Grube. 



