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



The second joint of the mandibular palp bears, in addition to the 

 usual set®, a short, plumose, dagger-shaped seta (Fig. 18). The ter- 

 minal claws of the palp are slender and smooth. 



The two prominent spines upon the first mandibular process of the 

 first maxilla bear teeth (Fig. 16). 



The palp of the second maxilla terminates in three long flexible 

 spines. The middle spine is longer than the whole palp, but the 

 lateral ones are only about two-thirds as long as the middle one. 



The first foot (Fig. 21) is five-jointed, the third and fourth joints 

 being distinct. The second joint is broad and is as long as the united 

 lengths of the next three joints. The terminal claw is longer than the 

 united lengths of the last three joints. The distal third of the cephalic 

 margin of this claw is finely pectinated. 



The claw upon the last joint of the second foot (Fig. 23) is curved 

 and is about twice as long as the terminal joint. 



The i^ost-abdominal rami (Fig. 19) are slender and straight. The 

 terminal claws are long and slender, being about half as long as the 

 ramus. They are straight and one margin of the tip of each is finely 

 pectinated. The lower claw is fully three-fourths as long as the distal 

 one and resembles it in structure. 



Habitat: These are found in great numbers in a shallow grassy 

 pool at Burlington, Ohio. They were found in the early part of 

 March, 1893, just after the close of a long and severe winter; indeed, 

 there was a light snow-fall the day before the collection was made. 

 Judging by the lay of the land, I think that the pool dries up in 

 summer. 



At Atlanta, Georgia, just after some heavy rains in January, 1894, 

 large numbers of these active creatures were found in several shallow 

 pools in the South Eiver bottoms. These pools dry up in warm 

 weather. The specimens remained for about two weeks and then dis- 

 appeared. Length 1.58 mm.; height 0.94 mm.; width 0.91 mm. Jones 

 Creek, Kent county, Delaware, March 3, 1894, collected by Professor 

 L. D. Hileland. These were immature specimens about 1.4 mm. long. 



Cypriiiotus grandis Chambers. 



Plate LXXIX, Figs. 1-9. 



. — Ctjpris grandis Y . T. Chambers (41), pp. 151-152, Fig. 1. 



IBSl .—Cypris grandis G. L. Herrick (86), p. 32. 



Length 3.60 mm. Height 2.09 mm. Width 1.39 mm. 



"Valve oblong, slightly sub- reuiform, highest behind the middle, 

 sloping thence regularly toward the anterior end, with a slight bulge 

 on the hinge-margin just where it rounds off in front. Greatest thick- 

 ness about the middle. In side view somewhat resembling Brady's 



