POLYCHJETA. BENHAM. 199 



The iiotopodial chaeta?., about 50 in number, are stouter 

 than the neuropodial, and are radiately arranged ; the 

 upper and anterior are shorter than the rest, but of the same 

 form ; they have a blunt point below which is a large number 

 of rows of minutely pectinated frills (PI. xl., fig. 49). 



The neuropodial chaeta?, about 70 in number, are in 7 or 

 8 tiers, with 3-6 (or even 7) in each tier (PI. xl., fig. 50) ; the 

 smaller number in the upper and lower, the larger number 

 in the middle tiers. There are some 23-25 frills in the longer 

 upper chaetae. The lower chaetae have, as is usual, fewer 

 frills than the upper, and are altogether shorter. 



There is no evidence of a subapical tooth (therefore 

 it would be placed in Malmgren's genus, Eunoa). Nor are 

 there any stout pectinations in the distal frill. 



The dorsal cirri are covered with short cylindrical papillae. 



The head is typically Harmothoid, but the peaks are 

 rather widely separated (PI. xl., fig. 46). The prostomium 

 is longer than broad, the anterior eyes are lateral at about 

 the middle of the side, and the posterior are far back, close 

 to the hinder margin. 



The tentacles are finely ciliated, the subterminal swelling 

 feebly marked. The median tentacle is much stouter than 

 the laterals, and about twice their length. 



The palps are longer than the median, as also are the 

 peristomial cirri. The tentacles, like the cirri, are trans- 

 parent. 



Yellow chaeta?. are visible on the upper side of the base of 

 the peristomial cirri. 



Remarks. JVTIntosh described in the " Challenger " Report 

 a species, Eunoa abyssorutn, from the south of Australia, in 

 2000 fathoms, which in some respects seems to resemble the 

 present species. But as that individual had no elytra, and 

 as the chaeta? differ in some details, and the form was eyeless, 

 it seemed desirable to establish a new species for it. 



In Eunoa opalina, from the Strait of Magellan, M'Intosh 

 describes and figures " soft papillae " on the elytra, but they 

 are short and broad. He refers also to the ' pellucid " 

 tentacles, and the widely separated peaks of the prostomium. 



But his figures of the chaeta? show differences in that the 

 apex of the neuropodial is much more hooked and sharper 

 at the tip, and that of the notopodial is longer and sharper 

 than in the present. 



