BY MARGUERITE HENRY. 29 



cervical sinus, rostrum present. Carapace marked with a rhomboiclal pattern. 

 Antennules immovable. Epbippium containing two eggs. 



Male. Smaller than the female. Head without a rostrum. Antennules 

 large and movable. First foot with a hook and long flagellum. 



This genus comprises over seventy species from different parts of the world, 

 all of which are subject to considerable variations. Only one species has thus 

 far been recorded from New South Wales. 



Key to varieties of Daphnia carinata 



A. Carina very greatly developed, forming a large expansion . . . . var. ceplutlata. 

 AA. Carina of ordinary .size. 



B. Spine straight var. intermedia. 



BB. Spine upturned. 



C. Rostrum recurved var. gravis. 



CO. Rostrum straig'ht var. magniceps. 



Daphnia carinata Kng {Syn. D. similis Claus.). 



First described by King (1852, p. 246) and later redescribed by Bars (1896), 

 both writers noting varieties. In 1914 Sars published a more detailed descrip- 

 tion to show the extraordinary variableness of the species. 



Female. Outline of carapace very variable, mainly due to the degree of 

 development of the carina surrounding the anterior portion; the posterior spine 

 may be very long, medium sized or greatly reduced. Head carinated, fornix 

 terminating on each side in an angular corner. Eye of moderate size, ocellus 

 small. Antennules very small. Post-abdomen with a straight dorsal edge, 10-14 

 marginal denticles, end-claws curved, short, bearing a row of fine spinules. 



Male. Smaller than female. Head without a distinct carina, carapace spine 

 long and slender. Antennules with a well developed flagellum. 



Distribution. — This species occurs in New South Wales, Victoria, Tasmania 

 and in New Zealand; also in Palestine and Syria. 



Typical form (Plate iv., fig. 1). 



Carapace somewhat oval in shape, narrowing posteriorly towards the base 

 of the spine. Head with a very acute rostrum, carina not very largely developed. 

 Posterior spine exceeds half the length of the carapace. Length up to 4 mm. 



Distribution. — N.S.W. : "Swamps near Sydney," Clyde, Farramatta, Corowa. 



Var. INTERMEDIA Sars. 



Carapace shorter and broader. Posterior spine coarser. Length not ex- 

 ceeding 3 mm. 



Distribution. — N.S.W. : Waterloo Swamps, Hay; Victoria. 

 Var. GRAVIS King. 



Carapace broadly oval, rostrum recurved, posterior spine slender, upturned. 

 Length 5 mm. 



Distribution. — Sydney, Melbourne. 

 Var. MAGNICEPS Sars. 



Carapace quadrangular, posterior spine very upturned. Head large. Length 

 3.5 mm. This variety has only been collected from swamps in the neighbourhood 

 of Sydney. 

 Var. CEPHALATA King (Plate iv., fig. 2). 



Carina very greatly developed forming a large expansion which is sharply 



