ObZ TKESHWATER ENTOMOSTEACA OP N.S.W. 11. COPEPODA, 



Cyclops axjstralis (King). 



Syn. — C. sydneyensis Sclimeil. 



This species was mentioned by King (1854) but no description or illustration 

 was given, merely the name and locality "in all ponds"; since this was the only 

 Cyclops mentioned by King, he probably united several species under the one 

 flame. Sars (1896, p. 74) briefly described a species of Cyclops from Australia 

 under this name, it being the only unknown member of the genus in a collection 

 sent to him from the neighbourhood of Sydney. The species was not figured 

 until 1908 when Sars published detailed drawings (Plate iii., fig's. 5-18). 



Female. Cephalothorax oval in outline, tapering more posteriorly than an- 

 teriorly. Abdomen equal in length to two-thirds of the cephalothorax, its genital 

 segment almost attaining the length of the three succeeding segments combined; 

 caudal rami elongated, slender, exceeding the length of the last two segments 

 combined, innermost apical seta very slightly longer than the outermost. An- 

 tennules very little longer than the first segment of the cephalothorax, consisting 

 of twelve segments of which the 8th and 9th are unusually long. Both rami of 

 the 1st pair of legs two-segmented, those of the three succeeding pairs three- 

 segmented. Fifth pair with the basal segment marked only by a seta, terminal 

 segment small, provided with a seta and a very small denticle. This is the 

 largest Australian Cyclops known, the adult female attaining a length of from 

 2 to 2.5 mm. 



Distribution. — N.S.W. : Byron Bay, Kendall, Centennial Park, Bourke Street, 

 Waterloo Swamps, University Pond, Holbrook, Corowa; Victoria; South Aus- 

 tralia. 



Cyclops varicans Sars. 



Sars, Christ. Videns. Sels. Forh., 1862, p. 43, Plate xxxiii. 



Female. Cephalothorax moderately robust, oval in outline, the greatest width 

 occurring in the middle; last segment sliglitly expanded lateraUy. Abdomen 

 greater than half the leng-th of the cephalothorax; the genital segment nai-rowing 

 posteriorly; caudal rami very slightly divergent, equal in length to the last two 

 segments combined, the innermost seta very much longer than the outer. An- 

 tennules composed of twelve segments, shorter than the first segment of the 

 cephalothorax. Natatory legs with both rami two-segmented, endopodites of the 

 4th pair with both apical spines well developed. Fifth pair of legs with the 

 proximal seg-ment much reduced, its presence only marked by a seta, distal seg- 

 ment small, its seta long and slender and with a minute spinule on the inner 

 edge. Length, .85 mm. 



Distribution. — This species has never before been recorded from Australia. 

 N.S.W.: Moss Vale, Berrima; New Zealand; North America; Africa; Turkistan; 

 xCurope. 



Genus Pachycyclops Sars, 1914. 



Lateral parts of the cephalothoracic segments not produced lateraUj', last 

 segTuent very small. Abdomen moderately slender, genital segment only slightly 

 dilated in front; caudal rami comparatively short, apical setae well developed. 

 Antennules long and slender, composed of seventeen segments. Natatory legs 

 with both rami composed of three segments; terminal segment of exopodite in 

 lst-3rd pairs with three spines outside, in 4th pair with two spines. Fifth pair 

 two-segmented, proximal segment with a slender seta, distal segment short, armed 



