66 D. T. SCOUHFIKLP ON HRITISH CLAOOCERA. 



two very much smaller projections. The number of eggs is 

 generally four. Epliippium witli one egg. Length ^\ in. 



My notes of its occurrence are as follows : — Wanstead Park, 

 Essex, May to November, 1890, March to November, 1891, 

 April, 1892 ; Filby Broad, Middle Dyke, and Ditch at Wrox- 

 ham, Norfolk, August, 1890 ; Higham Park, Woodford, Essex, 

 May and August, 1891 ; Eagle Pond, Snarcsbrook, Essex, 

 October, 1891 ; Royal Botanic Gardens, Regent's Park, London, 

 April, 1892 ; Gelding's Hill Ponds, Loughton, Essex, April, 1892. 



Male. — Colour same as female. Head large, dorsal and 

 ventral margins of the shell nearly straight. Shell markings 

 as in the female. Antennules but little enlarged, with a 

 flagellum barely twice as long as the terminal tuft of sensory 

 hairs. First feet with a hook and a long filament. Tail 

 practically the same as in the female. Length -^^ in. 



Wanstead Park, Essex, September and October, 1891. 



The form figured by Baird as D. reticulata, var. quadrangula, 

 may have been the ephippial female of the present species, 

 but the details given are scarc^ely sufficient to make the refer- 

 ence even moderately certain. 



Daphnia HVALiNA, Lcydig (Plate V, Fig. 1). — This is one of 

 the group of species of the genus Daphnia, which delight in 

 the clear water of ponds and lakes free from weeds. It comes 

 rather close to some of the varieties of D. lougispina, but is 

 more transparent, has a taller head, and fewer anal spines. 



Female. — Hyaline. Head rounded, and nearly one- third the 

 whole body length, but not much crested. Its ventral margin 

 is decidedly concave. Shell-spine very long, often one-half the 

 length of the animal. Shell markings rhomboidal. Compound 

 eye with prominent lenses arranged regularly around the 

 nearly black mass of pigment. Simple eye with a small spot 

 of dark pigment. Tail armed with from eight to ten anal 

 spines. Terminal claws smooth, i.e., without accessory teeth 

 Large specimens may sometimes be seen carrying from ten to 

 twelve eggs, or even more, but they are usually less numerous 

 than this. I have not observed the ephippial female. Length 

 Y^^ in; without shell-spine. Specimens from the Eagle Pond, 

 Snaresbrook, are usually less than this, however, while those 

 from Connaught Water, Cliingford, are occasionally more, even 

 reaching -jy^"- 



