228 



sloping gently behind, ventral margin slightly sinuated, anterior extremity 

 obtusely rounded, posterior produced to a blunt prominence located somewhat 

 above the longitudinal axis of the shell; seen dorsally, square-shaped, with 

 the width, between the tips of the aliform expansions, somewhat less than 

 the length, both extremities narrowly produced. Valves rather thin and pellucid, 

 with scattered small pits on the surface, alaeform expansions rather prominent, 

 triangular in shape, and projected about in the middle, each terminating in a 

 somewhat swollen blunt corner. Anterior antennae with the terminal part rather 

 thin and scarcely longer than the distal joint of the basal part, being distinctly 

 quadriarticulate. Posterior antennae of the usual structure. Legs rather slender 

 and produced, last pair with the 1st joint of the terminal part considerably 

 longer than the other 2 combined. 



Colour of shell whitish. 



Length of adult female 0.44 mm. 



Male unknown. 



Remarks. --This is also a very small species, and apparently nearly alliec 

 to tie preceding one, though easily distinguished by the considerably more 

 prominent alaeform expansions and their rather different form. The shape of 

 the shell is also somewhat dissimilar. 



Occurrence. A single female specimen of this form was found among 

 some Ostracoda collected at Riser, south coast of Norway, at depths ranging 

 from 10 to 30 fathoms. 



Distribution. West of Ireland. 



122. Cytheropteron angulatum, Brady. 



(PI. CV, fig. 3). 



Cytheropteron angulatum, Brady & Robertson, Ann. Mag. Nat. Hist, ser. IV, Vol. IX, p. 



PI. 2, figs. 7, 8. 



Specific Characters. Female. Shell of a peculiar angular appearance, with 

 the alaeform expansions rather slight, seen laterally, irregularly oblong oval in 

 shape, somewhat higher in front than behind, greatest height slightly exceeding 

 half the length, dorsal margin well arched in front of the middle, but sloping 

 gently behind, ventral margin slightly sinuated anteriorly and curving evenly 

 upwards behind, anterior extremity obtusely rounded, posterior somewhat 

 obliquely truncated, with the upper corner distinctly projecting, lower obsolete; 

 seen dorsally, rather irregular in outline, with the greatest width in front of 

 the middle and about equal to 3 /s of the length, side-edges evenly bowed in 



