74 KANSAS ACADEMY OF SCIENCE. 



two bristles; but the last has from five to six long bristles and one spine. 

 The second pair of antenna; consist of four segments of equal length. The 

 first two segments are provided on the interior surface with little hairs. The 

 mandible consists of one plastinated segment, and is similar to the mandible 

 described under C Clausii. Near the little terminal tooth itself there is a 

 rather long segmented bristle; but on the basal part of the mandible there 

 are two long and one short bristle. The maxilla is the same as in C. Clausii, 

 but is entirely without the stout spine which is beset with a few setie, which is 

 distinguished at the base of the two large terminal spines on the mandible of 

 C. Clausii. The fifth pair of feet consist of two segments. The basal seg- 

 ment has one long bristle;' the second has two, of which one is situated on 

 the summit of the segment, and the other on a small side-elevation. These 

 bristles are plain, not plumose. In the first abdominal segment there is a 

 cemental gland, which consists of three parts; the posterior, not divided, 

 and two front ones. The branches of the furca are each provided with 

 six plumose bristles. The longest of these is three times as large as the 

 furca. The last abdominal segment is posteriorly furnished with a row of 

 thin serrulations. The color is dirty yellow, and the pigment of the eye is 

 dark red. 



Cyclops Clausii. The length of the body in female is 1.9 mm.; with tail- 

 bristles, 2.4 mm. The body is longer and narrower than that of Cyclops sim- 

 plex. The first antennse are very long, and reach as far as the middle of the 

 fourth thoracic segment, and consist of seventeen joints. The last three seg' 

 ments are very long. The basal segment has several bristles and sharp 

 teeth, in form and disposition on the segment entirely corresponding with 

 the same little teeth of C. tenuicornis, Claus. The fourth and seventh seg- 

 ments are longest; the twelfth segment, besides the usual bristle, has also a 

 very transparent blade like appendage. The fifteenth and sixteenth seg- 

 ments are each provided with two bristles. The longitudinal ridge of the 

 seventeenth segment is compressed, and is also, as in"C. coronatus, Claus, 

 serrated. All the segments, except the last three, are also provided with 

 little teeth, which are disposed longitudinally and transversely; the trans- 

 verse rows are disposed in the same manner as in C. coronatus, CI., namely, 

 on the front edges of the segments, commencing with the fifth, and consist 

 of quite large teeth; the longitudinal rows consist of very small teeth, which 

 are distributed sometimes in separate groups. The second antennto consist 

 of four lengthened segments furnisheil in places with rows of seta3. The 

 basal segment is also provided with a very loug and plumose bristle, exactly 

 like the one in Cyclops tenuicornis. On the second segment there is to be 

 seen a transverse, obliquely disposed row of sharp little spines. The remain- 

 ing segments are the same as in C. coronatus, with a row of setae. The la- 

 brum is, as in the case of C. coronatus, furnished with thirteen blunt teeth. 

 The mandible is the same as that of tenuicornis, but its lateral depression is 

 not so deep, and both bristles, which are situated near this depression, are 



