128 REPORT OF NEW JERSEY STATE MUSEUM. 



firs*-- thoracic segment. Both anterior antennse in male forming 

 powerful hinged clasping organs, shorter than cephalothorax. 

 Posterior antennse unbranched, four-jointed. Mandible dilated 

 and toothed at extremit3^ Palp reduced tO' small tubercle which 

 bears two branchial filaments. Maxillary palp obsolete. Maxil- 

 lae themselves conical and bearing several strong curved apical 

 teeth and marginal setae. First pair of foot-jaws slender, armed 

 with several long marginal spines and setae, four-jointed. Sec- 

 ond pair much more robust, somewhat like first pair in Calanidce 

 third joint forming broad laminar process armed on margin 

 with powerful claws, and smaller apical joint bearing in like 

 rniarmer two slender claws and setas. First four pairs of swim- 

 ming-feet two-branched, both branches three- jointed. Fifth pair 

 rudimentary, composed of not more than three joints. One eye. 

 Two ovisacs. 



Species numerous, and very difficult to identify. This is due 

 to their extreme variability and plastic nature. Though numer- 

 ous nominal species have been described, but fifteen are admitted 

 by C. D. Marsh in his account of the North American species in 

 1909. Some of the forms have very wide distribution, ranging 

 over most of North America, Europe and Asia, without exhibit- 

 ing any differences in structure. Only one species included here 

 as identified positively from New Jersey, though doubtless most 

 of those in Marsh's work will be found eventually. 



Cyclops serrulatus Fischer. 

 Plate 34- 



Cyclops serrulatus Fischer, Bull. Soc. Imp. Nat. Moscow, XXIV, 1851, p. 423, 

 PI. ID, figs. 22, 23, 26-31. Sergiefskoje, near St. Petersburg, Russia. 

 (Not consulted.) 



— Byrnes, Cold Spring Harbor Monogr., VII, 1909, p. 27, PI. 12. Cold 



Spring Harbor, Long Island. 



C. D. Marsh, Trans. Wisconsin Acad. Sci. Art. Let., XVL pt. 2, No. 



3, 1909, p. 1094. PI. 88, figs. 5-9, PI. 89, §gs. 4-8. Cosmopolitan. 

 fCyclops setosa Haldeman, Journ. Acad. Nat. Sci. Phila., VIII, 1842, p. 331. 



Spring near Marietta, Pa. 

 Cyclops serrulatus var. elegans Marsh, Proc. U. S. Nat. Mus., XLII, 1912, p. 



245. Sodus Bay, Long Island. 



Description. — Cephalothorax rather evenly ellipsoid, broadest 

 nearly at middle, segments most all closely joined with smooth 



