KANSAS ACADEMY OF SCIENCE. 75 



shorter. The second pair of maxillipeds are distinguished by a very strong 

 development of the spine, which is situated on the jaw-feeler, and it is also 

 distinguished by the presence of a peculiar spine near the top of the raaxilli- 

 ped. This spine is also provided with three or four thick hairs. The max- 

 illipeds of the first pair have only this peculiarity, that all their bristles and 

 spines are thickly covered with long hairs, and besides, at the base of the 

 larger branch of the fifth foot, there is a long, plumed bristle. The swimming- 

 feet have all plumose setae. The first two segments are provided with trans- 

 verse rows of teeth. The fifth pair are of two segments, and are provided 

 with four bristles. The basal segment is furnished with a row of hair and 

 has one long, plumose seta. The terminal segment is furnished also with 

 three plumose setse, of which the middle is the longest and the other the 

 shortest. The first segment of the abdomen is very long and contains a 

 cemental gland, which is divided crosswise into two halves. The remaining 

 segments are quite short and have no furniture whatever, with the exception 

 of the last, which has on its posterior border a row of long spines. The 

 furca is shorter than that of C. simplex, and is not longer than the last seg- 

 ment of the abdomen. In each of its branches there is an oblique row of 

 teeth. The inner edges of the branches are plain, without hair. The tail- 

 bristles are plumose. The largest caudal seta is almost six times as long as 

 the furca. The color of the body is green. 



Cyclops latissimus. The length of the female is 1.85 mm. without the 

 caudal setse. This Cyclops is easily distinguished by its unusual width of 

 body, which has the appearance of a disc slightly flattened at the sides. The 

 rostrum is very large and somewhat bent, so that it is visible even when the 

 Ci/clops lies on its abdominal surface. The first abdominal segment is so 

 long that, in spite of the shortened form of the other abdominal segments, 

 the whole abdomen is almost equal in length to the front broad part of the 

 body. (The length of the abdomen with the furca is .78 mm.) The ante- 

 rior antennae are very long, namely, 1.2 mm,, and being composed of seven- 

 teen segments, reach almost to the first abdominal segment. The last three 

 segments are just as short as those of C. simplex; the basal, fourth and 

 seventh are the longest; they have several bristles, but, like the others, are 

 destitute of teeth. On the twelfth segment there is an oar-shaped organ. 

 The distinguishing characteristic of the antennae of C. latissimus is this : The 

 fourth segment has a very long and thick pale bristle, which is similar to 

 the same pale bristles ou the antennae of C. serrulatus, Fisch. The terminal 

 segment has six to seven long bristles and one short one. The second pair 

 of antennae consists of quite long segments, having neither setae nor spines. 

 Of all the segments of the body, only the fifth thoracic segment has furniture. 

 In the middle of this segment, both on the dorsal and the ventral surface, 

 there is a transverse line of quite small teeth. The lateral edges of the seg- 

 ments are furnished on each side with six strong spines, of which three are 

 directed forward and three backward. The rudimentary feet consist of 



