. Fresh-water biology. Freshwater biology. THE OSTRACODA 809. vsj Second antenna five-segmented in both sexes. Second leg termi- nating in one claw and one reflexed seta (Fig. 1256 6). Cyprois Zenker 1854. Only one species found in North America. Cyprois marginata Strauss 1821. Length mm., breadth mm., height o,g6 mm. Uniformly yellowish in color. An active, rest- less swimmer, and ai times tries hanging to the surface film of water. Somewhat resembling N. monacha in its swimming move- ments. May also creep on bot- tom debris. Grassy pools which later dry up. Sexual. Furca stout, sli
. Fresh-water biology. Freshwater biology. THE OSTRACODA 809. vsj Second antenna five-segmented in both sexes. Second leg termi- nating in one claw and one reflexed seta (Fig. 1256 6). Cyprois Zenker 1854. Only one species found in North America. Cyprois marginata Strauss 1821. Length mm., breadth mm., height o,g6 mm. Uniformly yellowish in color. An active, rest- less swimmer, and ai times tries hanging to the surface film of water. Somewhat resembling N. monacha in its swimming move- ments. May also creep on bot- tom debris. Grassy pools which later dry up. Sexual. Furca stout, slightly curved; dorsal seta uncom- monly long. April to July. Chi- cago, 111. (Jackson Park), April, May, June. Fig. 1256. Cyprois marginata. {a) Side view of female, X 25; (6) End of second leg, X 75: {c) Furca of female, X 60; {d) Maxillary spines, X 75. 22 () Natatory setae of the second antennae entirely lacking (Fig. 1298 c). Subfamily Candoninae . 91 23 (22) Natatory setae of the second antennae very evident, usually extend- ing at least to tips of terminal claws (Figs. 1268 e and 1290 c) 24 24 (25) Terminal segment of second leg with three long setae and no claws, â one seta reflexed (Fig. 1258 b). Ilyocypris Brady and Norman 1889 . 26 25 (24) Terminal segment of second leg with at least one claw (Fig. 12686),ââ and usually beak-shaped 28 26 (27) Shell with many prominent tubercles, knobs, and furrows. Nata- tory setae reaching to tips of terminal claws, or shghtly beyond Ilyocypris gihba Ramdohr 1808. Length to mm. Shell much tuberculate anteriorly and posteriorly, and decidedly furrowed anterodorsally. Two prominent tubercles just back of the eye-spot. Poor swimmers. Furca nearly straight, its terminal claws nearly equal in length, and plain. Terminal seta of furca about two-fifths length of terminal claw. Swampy regions, in mud, during the spring months. In company with /. bradyi, usu- ally. Colorado, March. Fig. 1257. Ilyocypris gibba. (o) Side view, X
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
