91 



simple and not projecting at all laterally; those of 3rd (antepenultimate) segment, 

 on the other hand, terminating in a very conspicuous prominent corner. Penulti- 

 mate segment, as usual, much smaller than the preceding ones. Tail considerably 

 exceeding in length ' 3 of the anterior division; genital segment rather dilated 

 in its anterior part and, like the other species, having the lateral edges clothed 

 with stiff hairs; posterior edge of this and the succeeding segment, moreover, 

 finely denticulate; anal segment longer than the preceding one. Caudal rami 

 somewhat produced, being about as long as the anal segment; apical setae rather 

 long and divergent. Anterior antennae very slender, equalling about in length 

 the cephalic segment, and composed of 20 articulations, all 3 joints of the 

 terminal part being well defined; proximal portion of the antennae comparatively 

 short and very sharply marked off from the narrow distal one. Posterior an- 

 tennae more slender than in A. simulans, and having the penultimate joint about 

 as long as the preceding one. Oral cone rather produced and gradually tapered, 

 extending about to the insertions of the 1st pair of legs. Mandibles with the 

 masticatory part long and slender; palp normal. Maxillae resembling in structure 

 those in A. simulans, though the setae of the inner lobe are comparatively longer. 

 Maxillipeds and natatory legs of normal structure. Last pair of legs with the 

 distal joint oval in form, and provided with only 2 apical setae. 



Body pellucid, tinged in some places with light yellow. 



Length of adult female 0.80 mm. 



Remarks. I cannot doubt that the above-described form is that recorded 

 by Brady in his Monograph as Cyclopicera lata. Brady believed this form to be 

 identical with Norman's Ascomyzon echinicola; but the form so named in Giesbrecht's 

 work and figured on PI. 2, II, is certainly a different species. On the other 

 hand, it would seem that Giesbrecht has confounded the present species and 

 A. Boecki Brady. In any case the coloured figure given on PI. 1 is unquestionably 

 referable to the present species and not to A. Boecki. The prominent lateral 

 corners of the antepenultimate trunk-segment will suffice for an immediate recog- 

 nition of the present species as distinct from any of the others. 



Occurrence. I have occasionally met with this form at Ris0r and Grimstad, 

 south coast of Norway, in moderate depths among algse, and a few additional 

 specimens were picked up from the bottom residue of the same collecting- 

 bottle in which A. Boecki and A. simulans occurred. 



Distribution. British Isles (Brady), Gulf of Naples (Giesbrecht). 



