5b4 FEESHWATEP ENTOMOSTRACA OF N.S.W. 11. COPEPODA, 



Distrihutioii. — N.S.W. : Kendall, Hornsby, Centennial Park, Bourke Street, 

 Bringagee. Holbrook; Victoria; Hawaii; Asia; North and South America; 

 Africa; and throughout Europe. 



Genus Leptoctclops Sars, 1914. 



Segments of the eephalothorax produced laterally, rounded at the ends; last 

 segment short and broad, produced on each side to a rounded hairy lobe. 

 Abdomen slender, genital segment short; caudal rami more or less elongated. 

 Antennules composed of twelve segments, the outer ones very slender. Natatory 

 legs with both rami three-segmented, armed as in the genus Pachycylops. Fifth 

 pair of legs formed by a trilobate lamella armed with a denticulated spine and 

 two setae. Seminal receptacle with the posterior part not produced, forming 

 two transverse bands. This genus comprises the species of Schmeil's "serrulatus- 

 prasinus" group. 



Two occur in New South Wales. 



Key to species of Leptocyelops. 



A. Antennules reaching the end of the second segment of the cephalothorax. agilis. 

 AA. Antennules reaching past the third segment of the cephalothorax . . viridis, 



Leptocyclops agilis (Koch). 



Syn. — C. serrulatus Fischer, C. varius var. brachyura Lilljeborg. 



Described by Koch in 1835, first recorded from Australia by Sars (1896). 



Female. Cephalothorax slender, oval in outline. Abdomen slender, equal to 

 two-thirds of the cephalothorax in length; genital segment dilated at the base, 

 equal to the combined length of the two succeeding segments; caudal rami of 

 moderate length, equalling the two preceding segments, diverging at the ends, 

 outer edges denticulated. Antennules composed of twelve segments, long and 

 slender, reaching the end of the second segment of the cephalothorax. Fifth pair 

 of legs with a large, coarsely dentate, inner spine. Length, 1 mm. 



Distribution. — This is the commonest "Cyclops" found in New South Wales, 

 and is distributed practically throughout the State. Some specimens were raised 

 from dried mud collected at Meryula Station near Cobar, N.S.W., Byron Bay, 

 Dorrigo, Bangalow, Kendall, Moss Vale, Berrima, Bong Bong, Yarrangobilly, 

 Lett Eiver, Leura, Orange, Epping, Lane Cove, Panramatta, Five Dock, Botany; 

 Victoria; New Zealand; New Guinea; Hawaii; Azores; Polar Island; Africa; 

 North and South America and throughout Asia and Europe. 



Leptocyclops "\'iridis Henry. 



Proc. Roy. Soc. N.S.W., liii., 1919, p. 40, Plate 2, figs. 8-9. 

 Distribution. — N.S.W. : Kendall, Hornsby, Epping. 



Genus Plattcyclops Sars, 1914. 



Cephalothoraeic segments expanded laterally; last segment short and broad, 

 with its lateral parts more or less densely hairy. Abdomen robust, genital seg- 

 ment short; caudal rami of different shape in the different species. Antennules 

 short, with the number of segments reduced. Natatory legs with the basal part 

 broad, both rami three-segmented and of almost equal length, middle segment of 

 the endopodite with a single seta inside. Fifth pair sometimes well defined, 

 formed by a small lamella bearing two setae and a spine or this replaced by 

 three spines. Seminal receptacle short and broad. 



