no. 1651. REPORT ON THE OSTRACOD A— SHARPS. 419 



leather leaf (Chamaedaphne calyculata) . Other shrubs noted were 

 the dwarf birch (Betula pumila), the alder (Alnus incana), the 

 swamp blueberry (Vaccinium corymbosum) , and the poison sumach 

 (RJius vernix). This region was also characterized as the home of 

 various orchids, the sundew {Drosera rotundi folia) , the pitcher plant 

 (Sarracenia purpurea), and the peat moss (Sphagnum). 



Observations. — These Ostracods were somewhat brownish yellow 

 in color, a little darker ventrally, and a light yellow blotch just 

 posterior to and below the eye-spot. There are two distinct eyes, a 

 red eye-spot surrounded by a black pigment band. They swim very 

 actively and persistently, remaining near the bottom most of the time. 

 They also resemble the Cladocera in many of their swimming 

 motions, at times turning so that the anterior part of the body is 

 upwards, until they reach the surface of the water, where they hang, 

 back downward, a very unusual and especially curious position for 

 an Ostracod. 



Distribution. — This form seems to occur only in permanent bodies 

 of pure fresh water which is also rich with aquatic vegetation. They 

 usually appear in April, and are abundant during the summer 

 months, disappearing in the early autumn. It has been reported 

 from all northern and middle Europe and from Minnesota.* A few 

 specimens were found by me near Clarke Junction, Indiana, May 12, 

 1906, in permanent dune ponds. Found in company with Gypris 

 fuscata, Cypria dentifera, and Gypridopsis vidua. 



2. Family CYTHERIDyE. 



15. Genus CYTHERE O. F. Muller. 



Cythere O. F. Muller, Entomos, seu Insecta testacea, 1785, p. 63. — Sars, 

 Forb. Vid. Selsk. Christiania, 1SG5, p. 28.— Dahl, Zool. Jahrb., Ill, 

 18S8, Heft 4, p. 605.— G.' W. Muller, Die Ostracoden des Golfes von 

 Neapel, 1894, p. 350, pi. xxvn, figs. 25-35 ; pi. xxvin, figs. 11-13, 15-18, 

 20, 28, 29 ; pi. xxix, figs. 11, 12, 14, 16. 



Shell thick, mostly pitted, without distinct flanges ; muscle impres- 

 sions 4, which form a row. The growing line runs at a moderate dis- 

 tance from the shell edge, however, in the anterior half this is 

 always nearer than the muscle impressions. 



Seen from above, always somewhat strongly compressed, not so 

 broad as high, compound eyes prominent. Hinge margin always 

 with large teeth on the right shell at its anterior and posterior ends. 

 The shell edges do not overlap anteriorly or posteriorly. 



First antenna short and thickset, 5-segmented, the penultimate 

 segment formed of the union of the fifth and sixth segments; the 

 penultimate and antepenultimate segments short, hardly longer than 



« Herrick, 10th Ann. Kept. Minn, Geol. and Nat. Hist. Survey, 1882, p. 252. 



