171 



Remarks. The identity of the above-decribed form with that originally 

 recorded by O. Fr. Miiller seems to me to be indoubitable. Lilljeborg has 

 however described as Cythere viridis another very different Cytherid, and for 

 this raison the specific name of the present form was changed by Norman to 

 that of cyamos. It is a very small species and may easily be taken for young 

 of C. lutea. On a closer examination it is however found to be well distin- 

 guished from any of the 2 preceding species, both as to the shell and to the 

 structure of some of the appendages. 



Occurrence. This small Ostracod is very common in the upper part of 

 the Christiania Fjord close to the beach among algse, and I have also taken 

 it in many other places, up to the Finmark coast. 



Distribution. Kattegat, British Isles. 



Fossil. Norway, Scotland. 



Gen. 36. Leptocythera, G. O. Sars, n. c 



Syn: Cythere auct. (part) 



Generic Characters. Shell, as a rule, narrow and elongated, much com- 

 pressed, with the valves subequal; surface in some cases roughly grooved, but 

 more frequently smooth and marked with more or less conspicuous pittings; 

 inner duplicatures moderately broad, marginal zone crossed by somewhat distant 

 pore-channels. Hinge well developped. Eyes confluent. Anterior antennae 

 comparatively short and stout, with the terminal part 3-articulate, carrying in 

 front 3 coarse spines, last joint more or less produced. Posterior antennae 

 with 2 apical claws; flagellum well developed in both sexes. Mandibular 

 palp rather narrow, with 3 comparatively short and stout spines on the ter- 

 minal joint; vibratory plate much reduced. Maxillae with the masticatory lobes 

 rather short; palp of moderate size. Legs, as a rule, rapidly increasing in 

 length posteriorly, basal part with only a single seta on the anterior margin. 

 Caudal lamellae with 2 rather distant bristles. Copulative appendages of male 

 with 2 backwards-pointing processes below the basal part; terminal part exerted 

 in front and behind to a projecting lappet. 



Remarks. In this new genus I propose to comprise a number of species 

 hitherto described as true members of the genus Cythere, but differing from 

 that genus, as defined above, by the very narrow and elongated shape of the 

 shell, the wholly confluent eyes, and also by some other particularities in the 

 structural details noted in the above diagnosis. The type of the genus is 

 Cythere pellucida Baird, to whi>h several other species subsequently detected 



