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Cincinnati Society of Natural History. 



The left foot reaches to the terminal joint of the right foot. 

 The inner ramus is club-shaped, bent toward the outer ramus, 

 and reaches to about the middle of the terminal joint of the 

 outer ramus. Its tip bears four or five small spines. The 

 two joints of the outer ramus bear numerous fine hairs on 

 their inner aspect. The terminal joint bears a seta plumose 

 on one side and a short spearhead-shaped projection. 



The inner ramus of the fifth foot of the female (Fig. 2) is 

 of small caliber and about as long as the outer ramus. It 

 bears two serrate spines of nearly half its own length and 

 three or four very small spines. The terminal claw is dentate 

 on both margins, and bears on its posterior margin two small 

 bare spines and a longer serrate one. 



Types are deposited in the U. S. National Museum, in the 

 Museum of the Cincinnati Society of Natural History (Acc. 

 Cat. No. 15,000), and in the zoological collection of the Uni- 

 versity of Nebraska, Lincoln. 



Whether this species is one which appears only temporarily 

 in the spring I can not tell. It appeared usually in temporary 

 pools. I found mature ova-bearing specimens April 10 and 

 June 3. I think it may stay the year round under favorable 

 circumstances. 



Diaptomus sanguineus Forbes. 



A species of small or medium size. The first segment is 

 equal to the remainder of the cephalo-thorax. The outer 

 segments are nearly equal. The last segment in the female is 

 armed with an unusually strong spine at its outer angle. 



The first abdominal segment in the female equals the rest 

 of the abdomen and furca. It is armed with strong lateral 

 spines about one-third of the length of those on the last seg- 

 ment of the cephalo-thorax. The second segment is about 

 one-half as long as the third. The furcae are longer than 

 broad, and may be ciliated on their margins. The antennae 

 reach to the middle of the furca. 



The fifth foot of the female is short and thick. The inner 

 ramus is scarcely two-thirds of the length of the first joint of 

 the outer. It bears two spines half its own length. The 

 claw is well curved and dentate along its inner aspect. On 



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