no.1758. ON MARINE COPEPODA IND CLADOCERA. SHARPE. 435 



Genus EVADNE Lov.n, 1836. 



EVADNE NORDMANNI Loven. 



Evadne nordmanni Loven, Kongl. Sven. Vet. Akad. Eandl., 1835, p. I. pis. 

 L-2, figs. 1-16.— Baikd, British Entomostraca, L850, p. Ml, pi. 17, fig. 2. 

 Saks, Forh. Vid. Selsk. Christiania, L890, no. I, p. 11. Lilljeborg, Nova 

 Acta Elegise Sue. Sci. Upsaliensis, sit. l, vol. 19, Mini, p. 642, pi. 86, li<_ f s. 

 4-17.— Apstein, Nordisches Plankton, Cladocera, Kiel. L901, p. L2, fig. '_'!'. 



Length of female from ().'.»<) to l.i.j mm. Height about one-half 

 the length. Males slightly smaller, and tapering more rapidly pos- 

 teriorly to a hyaline point. 



Seen from the side (fig. 20a) the female is more or less triangular, 

 depending upon the number of eggs in the brood sac. The body is 

 somewhat rounded posteriorly, tapering to a 

 small hyaline point. Head small, not sepa- 

 rated from the brood sac by a distinct invagi- 

 nation, and about one-third the length of the 

 resl of the body. The so-called neck gland 

 is situated nearly over the eye spot. Eye 

 spot as usual, large, somewhat triangular, 

 and with many long crystalline lenses. 



The brood sac may contain from three to 

 eight embryos, thus causing its outline to be 

 quite variable. Shell plain, quite 1 transpar- 

 ent, and with no especial marking's. Gray- 

 ish white to yellowish in color. 



h\ marks. — Collected in company with Po- 

 don leuckarti, Temora longicornis, Ponh/hi 

 meadii, Acartia tonsa, Centre-pages /i<t>n<itiis, and Labidocera sestiva. 



Occurrence. — Surface tows from Bureau of Fisheries wharf, Woods 

 Hole, Massachusetts, June to November. 



Distribution. — North Sea, April to August (Timm); Atlantic 

 Ocean (Hansen); North Atlantic (Lilljeborg); Narragansett Bay 

 (Williams); Norwegian Plankton (Apstein). 



Fig. 20. - Evadne nordmanni. 



a, SIDE VIEW OF female; h, SIDE 

 VIEW I IF MALE. 



BIBLIOGRAPHY. 



The bibliography here given includes only those names no! found in Williams' list 

 in the American Naturalist, vol. 40, no. 177, September, L906. 

 Apstein, ('. 



1901. Nordisches Plankton. VII. Cladocera. Kid, pp. Ll-15. 

 Baird, W. 



1846. On some new Genera and Species of British Entomostraca. Ann. Mag. 



Nat. Bist., vol. 17. 

 1849. Arrangement of the British Entomostraca, with a list of species. Trans. 

 Berwick Nat. Field Club, vol. 2. 



