210 ProceeMngi of the Royal Irish Academy. 



distinct glandular bands on the back between the parapodia, which bands 

 more and more completely encircle the body towards the hinder part, and 

 also on the posterior achaetous segment. Straight spines on the three 

 foremost setigerons segments. Uncial of the setigerous segments 4-5 (- 6) 

 considerably reduced, and without or with ouly very weak hair. The fully 

 developed uncini, whose inner and under contour is not bent out, have some 

 hairs and up to seven teeth. The anterior capillary setae have from the 

 very first setigerous segment weak side-teeth, which towards the hinder part 

 iacrease somewhat in strength. The long under setae, which have only traces 

 of side-teeth, exist (in indi^^duals which are not, or in any case not fully, 

 sexually developed) fi'om one to three in number on the fourth to the twenty- 

 second setigerous segments. The posterior capillary setae chiefly with rather 

 broad borders — wliich on the whole, however, grow smaller towards the 

 rear — and not particularly long poiuts. Tubes rather thin, and somewhat 

 flattened and closed up. 



Colour. — The anterior part as far as the thii'd setigerous segment is more 

 or less strongly speckled with brown, but further behiud the spots decrease 

 rapidly ; and moreover, the same segments on the ventral side, at least 

 towards the posterior region, are speckled extremely little or not at all. 

 The more or less varied distribution of the spots is shown in figs. 1.3- 15. 

 Especially conspicuous are the transverse bands and the strongly marked spot 

 outside each nuchal organ. In a very light-coloured iadividual from Blacksod 

 Bay there are only these last-named two spots, and a band of colour on the 

 posterior part of the head. Another indindual from the same locality has the 

 anterior part of the head very light-coloured. Here are found the two spots 

 on the side, but else only one in the middle of the anterior part ; this latter 

 can be distinguished as a rule in the more strongly coloured indi^"iduals. 



Cuimingham and Eamage (1) ^lite as follows concerning this species, 

 which they have obviously seen : — " The dorsal surface of the first few 

 somites is abundantly spotted with red and white." (PI. 47, fig. 41.) 



External Structure. — As in my earlier descriptions of Xicomache-species 

 (5), which are of course very much like one another in many cases, I can 

 express myself very briefly as regards the external structure of the body. 

 Bather few oceUi are found on either side of the front upper part of the head, 

 and they are seen best on the more faintly coloured indi\-iduals (fig. 15). 

 The nuchal organs, which can be clearly seen in fig. 1.3 (here drawn in a 

 somewhat different way from that adopted in my earlier figures), are rather 

 long and distinctly bent. 



The seven complete indidduals observed have all 22 setigerous segments 

 and one posterior achaetous segment. Of the 15 other posterior portions 

 observed, 11 are normally developed, while the remaining 4 have capillary 



