Copepoda Found in the Vicinity of Lincoln, Nebraska. 123 



exteriorly at the tip a finger-like projection, roughened on its 

 inner surface. Curved toward this, from the inner part of 

 the tip, is a spine very slightly plumose. The inner ramus 

 of both feet are covered with very short hairs. 



This species was found at Louisville in ponds made by the 

 removal of sand. It was found on both sides of the Platte 

 in similar places. The water was clear and deep with little 

 vegetation. The species is said to be littoral. 



DlAPTOMUS NKBRASKKNSIS n. Sp. (FigS. 1-4.) 



A rather large species, the female varying from 2.25 

 mm. to 2.5 mm. in length and the male being a little 

 smaller. The cephalo-thorax is considerably broadest in the 

 middle. The first segment is nearly half the cephalo-thorax. 

 The last two segments of the female are fused. The last 

 segment is asymmetrical in the male and still more so in 

 the female, the left side being produced further back (Fig. 4). 

 There is a small tooth at the exterior angle in the female. 



The first abdominal segment of the female equals the rest 

 of the abdomen and furca. It bears small lateral teeth. The 

 second segment is about half the length of the first and the 

 third very short. Caudal furcse a little longer than broad. 

 The spermatophores were frequently attached to the speci- 

 mens, and usually there were two or more, sometimes as 

 many as six. The egg sac contains an unusually large num- 

 ber of eggs. 



The antepenultimate segment of the male right antenna 

 is unarmed (Fig. 1). The joint proximal to the geniculating 

 joint is not much swollen. 



The basal joint of the right fifth foot in the male (Fig. 3) 

 bears a tubercle at the middle of the inner margin and a spur 

 at the inner proximal angle. The inner ramus is small and 

 hardly half the length of the first joint of the outer ramus. 

 The prominent characteristic of the species is a strong claw 

 borne on the back side of the basal joint, twice the length of 

 the inner ramus. The terminal joint is nearly rectangular, 

 with the accessory spine at the outer distal angle, and a regu- 

 larly curved terminal claw at the inner. The claw is dentate 

 more than half its length. 



5 



