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



what smaller and a weak pectinate seta one-fifth the length of the 

 stylet from the end; palp of mandible very bristly. The intromittant 

 organ of the male is more simple than those hitherto described, con- 

 sisting of a broad, flat basal segment on either side, with a coiled 

 ductus ejaculatorius and a funnel-shaped terminal portion consisting 

 of two opposable flaps. The basal segment is indistinctly two jointed 

 and those of both sides are seated on a common prominence. 



"Length of male 1.70 mm., of female 2.16 mm.; height of male 0.84 

 mm., of female 1.24 mm. The above measurements are too large, but 

 express the correct proportions. It is one of the smaller species." 



Habitat: 1 Alabama (Herrick, 86). 



GENUS CYPRIDOPSIS Brady. 1868. 



The antennule is seven-jointed. 



The antenna is five-jointed. The five natatory setse on the third 

 joint are plumose. 



The branchia of the second maxilla consists either of a plate bear- 

 ing five plumose setne or else of two sette which are inserted directly 

 on the blade. 



The second foot is five-jointed and bears, near its extremity, a 

 strong chitinous claw. 



The abdominal rami are rudimentary. 



The members of this species seem to be exclusively parthenogenetic. 



Cypridopsis vidua (O. F. Miiller.) 



Plates LXXII, Figs. 1-lg; LXXV, Figs. 5, 6, 8, 9; LXXVI, Figs. 4, 7. 



nSo.—Cypris vidua O. F. Miiller (149), p. 55; Taf. IV, Figs. 7-9. 



1820.— 3foiioculus vidua Jurine (98), p. 175; PI. XIX, Figs. 5-6. 



1837.— Cypris maculata Koch (102), H. 10, 2. 



1841.— " sirigata Koch (102), H. 36, 19. 



1844.— " vidua Zaddach (234), p. 35. 



1850.— " vidua Baird (5), p. 152; PI. XIX, Figs. 10-11. 



1850.— " sella Baird (5), p. 158; PL XIX, Figs. 5, 5a. 



1851.— " vidua Fischer (64), p. 162; Taf. XI, Figs. 1-2. 



1853.— " vidua Lilljeborg (118), p. 111. 



1854.— " vidua Zenker (238), p. 79. 



1868.— Cijprido2)sis vidua Brady (18), p. 375; Pi. XXIV, Figs. 27-36, 46. 



1868.— Cypris vidua Claus (48), PI. I, Figs. 6-8. 



1868.— " vidua Fric and Nekut (70), p. 48, Fig. 29. 



1869. — Cypridopsis ohesa Brady and Robertson (32), p. 364; PI. XVIII, Figs. 5-7. 



1870. — " ohesa Brady and Robertson (33), p. 15. 



I810.—Cypria vidua Heller (81), p. 90. 



1872.— " vidua Fric (69), 227. 



1874. — Cypridopsis ohesa Brady, Crosskey and Robertson (30), p. 128; PI. I, Figs. 1-4. 



1879.— C^pm vidua C. L. Herrick (83), p. 112; PI. XVII, Fig. 1. 



