Akwiosson — On some Irish Maldanidae. 21-3 



ill fully growu individuals' is 2-3^"*, (3-)4:", 5-6'"'", 6""", 5-6-°"--; a seventh 

 tooth can be traced on the fourteenth segment and perhaps on the adjoining 

 segments. 



On the fourth and fifth setigerous segments the upper uncini at least 

 lack bristles ; and accordingly it is not till the fouith seta reckoned fi'om 

 above, that bristles appear on these segments in the large individual investi- 

 gated. On the seventh setigerous segment no uncinus lacks bristles, but 

 even on the sixth setigerous segment the two or three uppermost uncini lack 

 bristles, or have only very feeble ones. 



The fully developed uncini (fig. 29) have their lower contour perfectly even. 



The points of the anterior capillary setae have, even so early as the first 

 to the third setigerous segments, distinct though slight side-teeth ; and these 

 afterwards increase somewhat, although they never perhaps become quite as 

 large as in Nicomache minor Arwidsson, whose setae they greatly resemble. 

 The long capillary setae underneath, which may be found in the fourth to the 

 twenty-second setigerous segments, have all but imperceptible traces of side- 

 teeth ; but so much of them one can see that one can determine that they 

 stand somewhat more closely towards the outer point of the setae. On the 

 fourth setigerous segment, for instance, two such setae have been observed, 

 and on the sixth and seventh setigerous segments three, one in each case 

 being particularly long. The posterior capillary setae have, on the three 

 foremost setigerous segments, rather broad borders, often of the same size on 

 each side ; towards the posterior regions one border at least may diminish 

 quite distinctly, but, as fig. 30 shows, there may be found here also two rather 

 broad borders of equal size. The points of these setae do not appear to be 

 particularly long : in any case such have not been observable in the material 

 at the disposal of the writer. As usual, the points are shortest on the foremost 

 segments. 



Size. — The largest individual from Howth attains a length of 45 mm., as 

 compared with a breadth of r2 mm. The largest individuals from Blaeksod 

 Bay are considerably smaller. 



Sexual Maturity. — The large individual just mentioned is a <y , taken 6th 

 October, 1909, and then at least near sexual maturity. 



Tubes. — Tubes observed from Blaeksod Bay are formed chiefly of small, 

 light-coloured grains of sand, amongst which may sometimes occur the shells 

 of small mussels. These are — -partly at least — closed up, somewhat winding, 

 somewhat flattened tubes, and are provided with grains of sand all the way 

 round. The outer diameter of a measured tube is 2-6 mm. as compared 

 with an inner diameter of rO mm. 



' For the system of notation used see ray eurlier treatise (5). 



