244 



marked porechannels, edges clothed with fine hairs. Eyes well separated; 

 immediately in front of them a rather conspicuous dark pigmentary spot. 

 Anterior antennae with the distal segment of the basal part oblong in shape, 

 gradually tapered towards the end and provided with a short seta at the infero- 

 posteal corner; terminal part only slightly attenuated, with the last joint rather 

 small, each of the 3 preceding joints with a rather stout spiniform seta 

 anteriorly. Posterior antennae comparatively strongly built, with the anterior 

 setiferous ledge of the penultimate joint placed opposite to the posterior ledge 

 at about the middle of the joint; vesicle leading to the flagellum unusually 

 large, club-shaped. Legs not much differing in size, last pair with the 1st 

 joint of the terminal part about the length of the other 2 combined. 



Male a little smaller than female, and having the shell comparatively 

 less tumid, with the infero-posteal corner somewhat more projecting. Copulative 

 appendages with a well-defined spirally curled string inside the basal part, 

 terminal part narrow linguiform in shape. 



Colour of shell more or less dark brownish orange. 



Length of adult female but little exceeding half a millimeter. 



Remarks. This form was recorded as early as the year 1858 by Bair 

 as a species of the genus Cylhere and was subsequently described under 2 

 other specific names, viz., by Lilljeborg as C. nitida and by Zencker as C. viridis, 

 being erroneously identified with the so named species of O. Fr. Muller. It 

 is the type of the present genus. 



Occurrence. The present Ostracod is a strictly littoral form, being found 

 rather frequently along our whole coast close to the beach among algae, and 

 often left in tidal pools together with other littoral animals. 



Distribution. British Isles, Kattegat, Baltic, Holland, Franklin Pierce Bay. 



Fossil. Norway, Scotland, Ireland. 



135. Xestoleberis depressa, G. O. Sars. 



(PI. CXI, fig. 2). 

 Xestoleberis depressa, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 68. 



Specific Characters. Female. Shell exceedingly tumid, with the posterior 

 part distinctly depressed, seen laterally almost semilunar in shape, greatest 

 height but little exceeding half the length, dorsal margin forming a rather even 

 arch quite continuous with both the anterior and posterior edges, ventral 

 margin slightly sinuated in front of the middle, anterior extremity considerably 

 tapered and distinctly deflexed, almost beak-shaped, though rounded at the 



