306 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. 



Cypria optlialmica Jurine. 



Plates LXXV, Figs. 1-3, 7; LXXVI, Figs. 1-3, 5. 



1820.— 3Ionoculus oj)tkahnicus J ariue (98), p. 178; PI. XIX, Figs. 16, 17. 



1835.— Cypris compressa Baird (I), p. 100; PI. Ill, Fig. 16. 



1837.— " punctata Koch (102), H. 21, p. 23, Fig. 23. 



1837.— " tenera Koch (102), H. 12, p. 3. 



1850.— " compressa Baird (5), p. 154; Taf. XIX, Figs. 14, 14a-c. 



1851.— " elegantula Fischer (63), p. 161; PI. X, Figs. 12-14. 



1853.— " compressa Lilljeborg (118), p. 112; PI. X, Figs. 16-18. 



185i.— Cypria imnctata Zenker (233), p. 77; Taf. Ill, A. 



1868.— Cypris compressa Brady (18), p. 372; PI. XXIV, Figs. 1-5; PJ. XXXVI, Fig. 6. 



1868.— " ovum Fric u. Nekut (70), p. 48, Fig. 30. 



1872.— " ovuni. Fric (69), p. 213, Fig. 28. 



1875.— " compressa Brady, Crosskey, and Robertson (30), p. 123; PI. I, Figs. 5, 6. 



1879.—.? Cypria neglecta Herrick (83), p. 112; PI. XVII, Fig. 2. 



1885. — Cypris punctata 'NoTdquist, (155) p. 150. 



1888.— " punctata Schwarz (199), p. 18. 



1888. — " compressa Sostaric (202), p. 47. 



1889.— Cypria opthalmica Brady and Norman (31), p. 69; PI. XI, Figs. 5-9. 



1891.— '• opthalmica Wenzel Vdvra (221), pp. 63-66; Figs. 19, 19i-19«, 20, 20i-20*. 



Length 0.55 to 0.58 mm. Height 0.37 to 0.40 mm. Width about 

 0.30 mm. 



The American representative appears to be somewhat wider than 

 the European type. 



The translucent shell is covered with irregularly scattered large 

 puncta. Near the two extremities, the shell bears long hairs. 



Viewed from the side the shell is reniform, widest back of the mid- 

 dle. Near the two extremities, the dark puncta are often so clustered 

 as to form dark blotches. Caudal, dorsal and cephalic margins con- 

 vex. Ventral margin is somewhat sinuate. 



Viewed from above the shell is ovate, the cephalic end somewhat 

 more narrow and more pointed than the caudal extremity. Hinge 

 line is straight. 



Viewed from below the contact line is sinuate. 



Viewed from the end the shape is oval, much higher than wide. 



For the structure of the female antenna consult Fig. 1. 



For the structure of the mandible consult Fig. 5. 



For the structure of the second foot consult Fig. 2. 



For the structure of the abdominal ramus consult Fig. 3. 



Habitat: ? Minnesota (Herrick, 83); Baxley, Georgia. The speci- 

 mens from Baxley were collected for me by Mr. A. B. Whitby. The 

 figures were drawn from Baxley specimens. 



