BYRNES: CYCLOPS OF FRESH WAIKR. 31 



segment and bearing a curved spine externally and a terete termi- 

 nal segment . . . which has an apical seta, four times its own 

 length." The Cold Spring Harbor Cyclops of this type gives no 

 evidence whatever of having more than a single segment in its 

 fifth foot. Following the nomenclature of Professor Marsh, how- 

 ever, this form is nevertheless to be regarded as C. bicolor in which 

 the fusion alluded to by Herrick is complete, if indeed we are justi- 

 fied in assuming that the fifth foot ever contained more than one 

 segment. Having but a single specimen, it is not possible to dis- 

 cuss this point profitably, but in the instance cited, the relation 

 of parts is unequivocal. 



Cyclops Phalcratus (Plate XIV.). 



C. phalcrafiis has been found rather widely distributed in the 

 collections made on Long Island, though it has not been found 

 abundant in any one locality. In my experience it frequents shal- 

 low fresh water j^^nds. It can be easily recognized by its plung- 

 ing movements in the water and by the ease with which it crawls 

 over dry surfaces. 



In general apearance C. phalcratus is opaque. It is relatively 

 thick in body, the abdomen tapering but slightly behind the cephalo- 

 thorax. C. phalcratus is often highly colored ; orange tones pre- 

 vailing over the body excepting the second thoracic segment which 

 is usually quite colorless, although some authors call it blue. The 

 ova within the body are a dull blue. 



The antenn?e contain as a rule eleven segments ; in a single 

 instance one individual had ten segments in one of its antennre, 

 but onl\- on one side of the body. h^ig. 3. Plate XI\'.. shows the 

 left antenna with ten segments; the right antenna of the same 

 individual is shown in Fig. 4, with eleven segments. The eleventh 

 segment is evidently formed by the division of the elongated sixth 

 segment at the level of the long hair it carries. This division 

 results in the formation of a small sixth segment and a longer 

 seventh segment in the eleven- jointed antenna. Herrick noted 

 that the antennae were usuall\- ten-jointed, but were frequently 

 eleven-jointed. It seems probable that the greater number of seg- 

 ments is to, be regarded as the ultimate condition of the species 

 rather than as a case of variation. The rami of the swimming 

 feet are three- jointed with a terminal armature as follows : 



