Ostracoda 5 



in the group Eucypridae, I have felt justified in regarding it as the type of a 

 particular genus, for which the above name is proposed. The female sex only 

 has hitherto been observed. By the examination of the male specimen de- 

 scribed below I have been still more confirmed in the generic distinctness of the 

 present form. 



4. Cypriconcha barbata (Forbes) 



Plate II 



Cypris harbata Forbes, Bulletin of the United States Fish Commission 

 for 1891, p. 214, PI. XXXVII, figs. 2, 3, PI. XXXVIII, Washington, 1893. 



Herpeto cypris barbata Turner, Freshwater Ostracoda of the United States 

 (in C. L. Herrick, Synopsis of the Entomostraca of Minnesota, p. 316, PI. 

 LXXVII, 1895, Second Report State Zoologist). 



Specific Cha&actbrs.— JlfaZe. Shell, seen laterally (fig. 1), oblong, uniform 

 in shape, rather higher behind than in front, greatest height about equal to half 

 the length, dorsal margin almost straight in the middle and sloping rather 

 steeply behind, more slowly in front, ventral margin distinctly sinuated in front 

 of the middle and conspicuously bowed in its posterior part; anterior extremity 

 somewhat defiexed and obtusely rounded at the end, posterior considerably 

 broader and rather oblique, with the lower corner quite evenly rounded off. 

 Seen dorsally (fig. 2), narrow oblong in outline, with the greatest width scarcely 

 exceeding ^ of the length, side-edges nearly straight in the middle, both extrem- 

 ities pointed, the posterior more so than the anterior. Valves perfectly equal, 

 with the surfaice smooth, but all over clothed with rather coarse hairs, forming a 

 dense fringe around the anterior extremity; inner ■ duplicatures remarkably 

 broad behind, and defined inwards by a sharply marked, curved line (see fig. 1)., 

 Anterior antennae (fig. 3) rather slender, with the terminal part almost twice as 

 long as the basal one and, las usual, composed of five joints, the first of which 

 is about the length of the two succeeding ones combined; setae of this part 

 slender and elongated, forming together a dense, apical fascicle. Posterior 

 antennae (fig. 4) not nearly so powerfully developed as in the genus Cypris, 

 with the penultimate joint much shorter than the preceding one and rather 

 narrow, sublinear in shape; natatory setae present in the usual number and 

 distinctly ciliated, extending however not fully as far as the apical claws; the 

 latter distinctly denticulated. Anterior lip (see fig. 5) somewhat protuberant in 

 front. Mandibles (fig. 6) well chitinized and coarsely dentate at the extremity; 

 palp of moderate size and rather densely setiferous, with the vibratory plate 

 comparatively large and provided with six plumose setae, five on the trans- 

 versely truncated extremity, and one rather smaller on the anterior edge. 

 Maxillae (fig. 7) with the spines of the outermost masticatory lobe smooth; 

 palp considerably produced beyond this lobe; vibratory plate large, semilunar 

 in shape. Maxillipeds (fig. 8) transformed in the usual manner, the palp being 

 developed to a powerful, grasping organ, that on the right side somewhat larger 

 than that on the left (fig. 9), and having the thumb like process of the propodus 

 considerably more prominent; dactylus moreover exhibiting at the base a well- 

 marked, tridentate, lamellar expansion, only faintly indicated on the left palp. 

 Anterior legs (fig. 10) considerably more slender than in the genus Cypris with the 

 terminal part distinctly four-articulate. Posterior legs (fig. 11) still more slender, 

 with the apical joint knob-like and armed with a somewhat hamate spine and a 

 recurved seta (see fig. 12). Caudal rami (fig. 13) exceedingly long and slender, 

 almost attaining half the length of the shell, and somewhat flexuous, dorsal 

 edge with about eight succeeding combs of spinules, apical claws (according to 

 Forbes) contained about two and a half times in the length of the ramus.* 



*These claws were broken off in the specimen examined by me; they are, however, added in the 

 figure from the drawing given by Forbes. 



