ENTOMOSTRACA OF MINNESOTA. 83 



loug as the two remaining joints. The second joint is trapezoidal, 

 shortest withi n. The third j oint is about half as wide at base as the first, 

 is straight without, with a sharp, small tooth at its distal third, and 

 bifid at tip. On the inner margin this joint is at first dilated a little, 

 and then deeply excavated to the narrow tip, to receive the lower end 

 of the left leg, the lower two- thirds of this margin forming the segment 

 of a circle. 



"The right leg is two-jointed, the first joint twice as broad, enlarged 

 at the lower end, forming an auriculate expansion at its inner inferior 

 angle. The second joint is conical in outline and about two-thirds as 

 long as the first. 



"The terminal bristles of the rami are very broad and strong in the 

 female, the outer one especially having an extraordinary size and 

 thickness. There is also at the outer angle of each ramus a short, 

 stout spine, that on the left ramus being inflated like the outer bristle. 

 Length .065 in. 



"The legs of the fifth pair in the female are three-jointed and simi- 

 lar, the basal joint short and broad, the second two and one-half times 

 as long as wide. The leg terminates by four diverging teeth, preceded 

 by two others, one on each side. 



"Taken in the towing net abundantly in October, 1881, at Grand 

 Traverse bay; also obtained rarely by Mr. B. W. Thomas, from the 

 city water of Chicago." 



Occurring in Minnesota, probably in Lake Superior. 



* Episcbura fliiviatilis Herrick. 

 Plate XIII, Figs. 14, 16. 

 Herrick '83, '84 and '87; De Guerne and Richard '89. 

 "Similar to the above but smaller (0.04 in.). The females are very 

 similar, though the fifth feet are more elongate and differently spined. 

 The abdomen is perfectly straight and the three caudal setie are of 

 nearly equal size. The claw is armed with eight teeth, all but the first 

 of which are emargiuate. The abdomen of the male is straight, but 

 has a strong process on the left side which bears a movable claw 

 laterally and a small second segment which terminates in two small 

 spines. The fifth foot of the male is peculiar; the inner ramus (or the 

 left foot) lamelli form, one-jointed, with two opposable claws; the right 

 branch is simple and three-jointed, in form like that of the female. 

 Here we have the most marked difference between the two species. 

 Found in Mulberry creek, Cullman county, Ala. Although a consid- 

 erable number were examined no oviferous females were found, while 

 the males contained the spermatophores and can hardly be thought 

 immature, and, as it is in the male that the most marked differences 

 appear, the two species seem certainly distinct." 

 6 



