Sludios on marine Ostracods 515 



species of this genus, as the latter stop a good distance distally of the nodous teeth.) The second- 

 ary claws never seem to be annulated. 



The lateral e y e s are well developed. The m c d i a n e y e is bare. 



Male: — 



Shell: — Length, 1,7 — 1,75 mm.; length : height about 2,27 :1. Seen from the 

 side (fig. 3) it has the same elongated type as the female, but is somewhat less regular. Its 

 greatest height is at about a third of the way along the shell and the anterior part of the shell 

 dominates to some extent over the posterior part. The dorsal and ventral margins converge 

 gently backwards from the point where the shell is highest. The dorsal margin is somewhat 

 irregular, it is somewhat flattened anteriorly and is characterized by a gentle and broad arcuation 

 somewhat in front of the middle of the shell and a similar arcuation just in front of the place 

 where it passes into the posterior margin. The ventral margin is slightly and almost evenly 

 arched, somewhat flattened anteriorly. The posterior margin is evenly and rather strongly 

 curv^ed, passing into the ventral margin with a broadly and evenly rounded line; it is bounded 

 from the dorsal margin by a broadly rounded corner, which is only slightly distinct. The 

 anterior margin is boldly rounded and passes evenly into the dorsal and ventral margins. 

 The part situated ventrally of the incisur is about as large as the rostrum. Seen from 

 below (fig. 4) it is narrowly oviform with its greatest breadth at about a third of 

 the distance along and the anterior part somewhat larger than the posterior part. The 

 wreath of hairs round the posterior part of the shell is rather dense. Seen from 

 inside: The medial bristles are perhaps somewhat fewer than in the female. Otherwise 

 the shells are alike in both sexes. 



First antenna (fig. 11): — This has seven joints. The proportion between the 

 joints are about the same as in A. norregica; cf. the description of the genus. Of the anterior 

 bristles on the third joint nos. 3 and 6 especially are very much shortened; the equipment of 

 these bristles is about the same as in the female, only somewhat weaker. The longer of the two 

 posterior distal bristles on the fourth joint is considerably shorter than the total length of the 

 three distal joints; even calculated absolutely it is in most cases somewhat shorter than that 

 of the female. The sensory bristle of the fifth joint is very much more powerfully developed 

 than in the female; its stem is thick and about as long as or somewhat longer than the total 

 length of the three distal joints; it has very numerous sensorial filaments. The a-claw is smooth. 

 The b-bristle is about as long as the anterior side of the second joint or is somewhat shorter; 

 it has six sensorial filaments. The c- and f-bristles are subequal and are about one and a half 

 times the length of the shell; a length of 2,5 — 2,7 mm. was observed; the c-bristle has 25 — 29, 

 the f-bristle 23 — 26 sensorial filaments. The g-bristle is about as long as the anterior side of 

 the second and third joints; it has nine sensorial filaments. 



Second antenna: — The exopodite is very much lengthened relat- 

 ively; its two proximal joints especially are considerably longer than the corresponding 

 joints in the female. The relation between the lengths of the joints is shown by the 

 following figures: 



3 (shell 1,7 mm. long) = I : II : (III —IX) -: 34 : 17 : 22. 



•■o^ 



