258 



144. Paradoxostoma ensiforme, Brady. 



(PI. CXVII, fig. 1). 



Paradoxostoma ensiforme, Brady, Mon. British Ostracoda, p. 460, PI. XXXV, figs. 811. 

 Syn: Paradoxostoma angustnm, G. W, Miiller. 



Specific Characters. Female. Shell rather elongate, seen laterally almost 

 ensiform in shape, with the greatest height not nearly attaining half the length, 

 dorsal margin somewhat abruptly arched behind the middle and sloping at a 

 nearly straight course to the tip of the hind extremity, ventral margin slightly 

 sinuated in front of the middle and evenly bowed behind, anterior extremity 

 narrowly produced, posterior terminating in a well-marked obtuse corner 

 located about in the longitudinal axis of the shell; seen dorsally, narrow 

 oblong in outline, with the greatest width in the middle and about equal to 

 Va of the length, side-edges somewhat irregularly curved, anterior extremity 

 more contracted than the posterior. Valves rather thin and pellucid, with the 

 surface very smooth and polished, inner duplicatures comparatively narrower 

 than in the type species. Anterior antennae considerably prolonged, with the 

 1st joint of the terminal part fully as long as the distal segment of the basal 

 one and somewhat exceeding the length of the 2nd joint, last 2 joints however 

 rather small and combined not nearly attaining half the length of the preceding 

 one. Posterior antennas comparatively slender, with the dividing suture of the 

 penultimate joint located somewhat above the middle, principal apical claw 

 much more prolonged than in the type species. Legs resembling in structure 

 those in that species, though having the apical claw more slender. 



Male slightly smaller than female, but very little differing in the shape 

 of the shell. Copulative appendages far less strongly built than in the pre- 

 ceding species and rather dissimilar in shape, basal part subtriangular in shape 

 and provided at the end in front with a small slightly bilobular prominence 

 and below with a rather large somewhat curved lamella; terminal part narrow 

 spiniform and doubled upon the said lamella so as forming together with it 

 a sort of pincers. 



Colour of shell not yet ascertained. 



Length of adult female 0.74 mm. 



Remarks. The present species bears some resemblance in its general 

 appearance to P. variabile, but is, on a closer comparison, easily distinguished 

 by the much more elongate shell, which seen laterally, exhibits a somewhat 

 ensiform shape; hence the specific name proposed by Brady. The form 



