103 



large, subquadrangular, lateral parts but slightly expanded, frontal edge trans- 

 versely truncated. Segments of mesosome with the lateral parts bluntly truncated. 

 Caudal segment circular in outline, lateral edges serrated, tip bluntly produced. 

 Eyes rather large, rounded oval. Superior antennae scarcely reaching beyond the 

 middle of the penultimate peduncular joint of the inferior ones, flagellum but little 

 longer than the peduncle, and composed in female of 8, in male of 12 articula- 

 tions. Inferior antennae in female not nearly attaining the length of the body, 

 in male considerably larger, equalling the body in length. 1st pair of legs in 

 female a little shorter than the next succeeding, but of the very same structure; 

 those of male more than twice as large, almost attaining the length of the whole 

 body, carpal joint oblong fusiform and, like the other joints, densely clothed with 

 short spiniform bristles. Middle piece of male operculum produced at the end, 

 on each side, to a lanceolate lappet minutely bifid at the tip. Urojjoda much 

 shorter than the caudal segment, and clothed with scattered fascicles of spiniform 

 bristles, inner ramus somewhat longer than the basal part, outer, considerably 

 smaller. Body yellowish, mottled everywhere with reddish brown specks. Length 

 of adult female 4 mm., of male 6 mm. 



Remarks. — As above stated, this is as yet the only known species of the 

 genus, and may easily be recognized from Ianira maculosa, to which it bears 

 some resemblance in colour and external appearance, by the comparatively much 

 shorter antennae and uropoda. 



Occurrence. — I have only met with this form off the west coast of Norway, 

 in the neighbourhood of Bergen. In one locality, at Bratholmen, it occurred in 

 considerable numbers on the roots and stems of Laminariae overgrown by Hydroida 

 and Polyzoa. 



Distribution. — Bohuslan (Bovallius). 



Gen. 4. Iaera, Leach, 1813. 



Syn: laeridina, M.-Edw. 



Generic Characters. — Body, as a rule, broad and much depressed, with 

 the lateral parts of all the segments laminarly expanded and fringed with bristles. 

 Cephalon broad, without any true rostrum, but with the lateral parts considerably 

 produced. Caudal segment with a more or less deep apical emargination, within 

 which the uropoda are contained. Eyes distinct, dorsal. Superior antennae ex- 

 tremely small, with the flagellum rudimentary. Inferior antennae of moderate 



