Arwidsson — On some Irish Maldanidan. 215 



hand, is quite free from glands at the back. The two obliquely extended spots 

 of glands on the front upper part of the eighth setigerous segment (5, fig. 118) 

 are here very straight, which may of course be connected with the fact that, 

 in the individual in question, this segment is much extended and also of more 

 even breadth, only tapering off somewhat in the very front part. The number 

 of uncini on the 19 setigerous segments, of which, however, only the fourth 

 to the eighth are fully developed to the normal extent, is as follows : 

 1, 2, 2, 4, 4, 4, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1-2. 



In connexion with this Leiochone species it may be mentioned that one 

 individual of the Leiochone species earlier cited, which is near akin to or is 

 identical with L. clypeata Saint-Joseph, possesses a fully projecting proboscis, a 

 thing which I for my part have never before had the opportunity of observing 

 in any species of this genus. This completely visible proboscis now shows 

 that the papuliferous part is developed all round, although it is shorter 

 forwards, it is true; Saint- Joseph (3, p. 140), speaking of L. dypmta, says: 

 " une trompe globuleuse tres vasculiere." In an earlier paper (5, p. 143), 

 chiefly with regard to the conditions prevailing in L. borealis (p. 157)— in 

 which, however, as mentioned, I have never had occasion to notice a 

 completely projected proboscis — I have conceived the papilliferous part of 

 the proboscis as almost vanishing in front of the mouth within the limits of 

 the tribus Leioehonini : this conception, therefore, needs a certain amount of 

 modification. Possibly in respect of proboscis -structure, as in several other 

 respects, the various Leiochone species are essentially dissimilar. 



Praxillella affinis (Sars) Arwidsson. 



Of this species — formerly known only from Scandinavia (Kattegat and 

 the Bergen region) — there are two mutilated individuals from the south coast 

 of Ireland, or, more precisely. Station K. 31 (8, p. 127), or 6 miles S.E.S. of 

 Mine Head, 53 m. Of one individual there remain the third to the eighth 

 setigerous segments, of the other the third to the seventeenth. Besides these 

 there is a posterior extremity, possibly belonging to one of the foregoing. All 

 the parts correspond very exactly with Scandinavian individuals (5). Amongst 

 other things are found the specially developed capillary setae on the tenth 

 and the eleventh setigerous segments. 



Genus Caesicirrus n. gen. 



Generic Diagnosis. — Nuchal organ of medium length. Distinct head 

 borders. The papillae of the proboscis are low or altogether absent. Segment 

 with collar is absent. The parapodia of the eighth setigerous segment in 

 the hinder part of the segment. There are distinct posterior achaetous 



