Arwidsson — On some Irish Maldanidae. 223 



very considerably increased, and these capillary setae are in every respect 

 very fine. 



The posterior capillary setae possess comparatively short points on the 

 first three setigerous segments ; the borders — both of the two or only one — 

 are here pretty broad (fig. 23). Towards the hind part of the body the 

 borders diminish gradually ; but one is always broader than the other, and 

 even on the hindmost segments of no inconsiderable breadth. The points 

 themselves increase in length backwards, to begin with ; nevertheless the 

 narrow extreme point on a number of the bristles is comparatively short, since 

 the point at the base is, so to speak, somewhat enlarged. These broadened 

 points begin on the sixth setigerous segment, after which they are distinct 

 in the seventh to the ninth setigerous segments. On the next segment 

 no such points have been observed ; but on the eleventh and on the twelfth 

 setigerous segments they again begin to assume this form, which is most 

 strongly developed on the next segment (fig. 24). On the fourteenth 

 setigerous segment these broadened points diminish ; and, from the fifteenth 

 setigerous segment onwards, many of the iipper setae seem to lack them 

 altogether. 



It would seem as if the posterior setae on the eighth and the ninth setigerous 

 segments — that is to say, where the anterior capillary setae are especially fine 

 and numerous — are not so numerous as on the other segments. The material 

 at my disposal, however, has not permitted a definite settlement of this 

 question. 



Size. — The two largest individuals investigated by me were taken in 

 Blacksod Bay, Station W. 115 ; the one which is complete, and which has been 

 preserved within its tube, measures 85 mm. in length ; its posterior region, 

 however, in particular, is drawn together, not to say folded up. Its greatest 

 breadth is 1-2 mm. The forward end of the second large individual measures, 

 up to its twelfth setigerous segment, 48 mm. in length ; this individual is 

 somewhat larger than the former. 



Sexual Maturity. — The two individuals just mentioned, which are both 

 5 $ and which were taken on 16 September, 1909, are fairly full of eggs 

 which are still of different sizes ; in the first ? the largest eggs attain a 

 magnitude of 0'22 x 0"28 mm. 



Ttibes. — The tubes are rather thin and brittle, and seem in all localities to 

 be composed, besides the inner light-coloured membrane, of a layer of fine 

 grains of sand, chiefly light in coloui-. That one of the two largest individuals 

 just named, which is complete, possesses a tube whose external diameter is 

 1-7 mm. For further particulars about the tubes see " Information about 

 Earlier Finds," 



