ENTOMOSTRACA OF MINNESOTA. 85 



The fifth legs of the female are broader proportionally than those 

 of lacustris but more slender than those of E. nevadensis. The last seg- 

 ment is four times as long as broad and bears six (7) teeth, of which 

 four are terminal. The second, third and fifth segments of the male 

 abdomen bear lateral processes extending toward the right. The first 

 three segments are subequal. The lateral process of the second has 

 the form of a stout but thin lamina projecting to a distance equal to 

 the width of the segment; it is acute at the apex, with the point a 

 little recurved, convex and smooth in front, and nearly straight be- 

 hind, except that this edge is irregularly serrate throughout and 

 deeply emarginate where it joins the segment. This blade is strongly 

 curved ventrad like the following. The third segment bears a broad 

 thin lamina which projects outward, as wide as long, broadly rounded 

 at the end, simple but strengthened beneath by a ridge of chitin. 

 From the fourth segment spring two processes, the ventral being 

 nearly similar to that of nevadensis. The dorsal process is a small 

 irregular plate curving forward, inward and downward. Length of 

 female 2.12 to 2.4 mm. 



* Epischura uordeiiskioeldi Lilljeborg. 

 Plate XI, Fms. 2, 5, 9. 

 De Gaerne and Richard '89. 

 This species, from St. Johns, Xewfoundland, is the largest of the 

 genus (2.9 mm.) and is remarkable for the slender, slightly armed ab- 

 domen. Cephalothorax robust, abdomen exceedingly slender, four- 

 jointed in the female, anterior two somewhat fused, third segment 

 longer than the fourth. Caudal stylets twice as long as wide, ciliated 

 internally; caudal setee similar and equal. Male abdomen five-jointed 

 and slightly flexed toward the right, second and third joints equal and 

 half as long again as the first. The second joint is armed with a rather 

 small, slightly curved, and notched at the tip. The process of the 

 third joint is very small and acute; that from the last is directed 

 cephalad and is blunt. Antennte reaching to base of stylets, 25-joiuted. 

 Geniculate antenna with the jienultimate joint unarmed. Feec of 

 fifth pair in the female uni ramose, three-jointed, nearly as slender as 

 in E. lacustris though less so tlian E. fliiviatilis, the joints nearly of equal 

 length. The left fifth foot of the male closely resembles that of E. 

 columbiw; the right diifering from the other forms in having an acces- 

 sory spine near the base of the inner aspect. 



GENUS OSPHRANTICUM Forbes. 1882. 



( ^Potamoichetor, Herrick. ) 

 First reported as Fotamoiehetor before the Minnesota Academy of 

 Sciences in 1879, but owing to a disastrous fire, publication was pre- 

 vented. Priority probably belongs to Forbes' name, since, although 



