382 EEV. A. M. NORMAN AND ME. G. S. BEADY 



ventral margin, the large size of the teeth at the infero-posteal 

 angle of the carapace ; the conspicuous reticulated sculpture of 

 the shell ; and the unusual form of the short abdomen with its 

 simple claws are all very marked characteristics. 



Until recently we had always regarded this as the Alona reticu- 

 lata of Baird,- but Schoedler has now described and figured a 

 species from Prussia, which appears to more closely agree with 

 that author's description and figure than does the form known 

 to ourselves. Had it been the Z. testudinarius which Dr. Baird 

 was describing, it seems very unlikely that he would have omit- 

 ted all notice of the remarkably large teeth at the infero-posteal 

 angle ; but on the other hand, with the exception of this omis- 

 sion, and the remarkable difference in size ascribed to A. reti- 

 culata, both the description and figure given in the "Natural 

 History of the British Mitomostraca" closely accord with Z. tes- 

 tudinarius. It must be understood, however, that while this 

 species is certainly not the A. reticulata of Schoedler (but the 

 same as that named by him A. esocirostris), and is perhaps not 

 that originally described by Dr. Baird, it is the species thus 

 named by Lilljeborg and G. 0. Sars. 



Lynceus testudinarius inhabits all those parts of the Continent 

 of Europe where the Entomostraca have been carefully examined, 

 viz., the countries of Bussia, Prussia, Sweden, and Norway. In 

 the British Islands it is not uncommonly found in the lakes and 

 clearer ponds. We have taken it in Crag, Grindon, Darden, 

 Chartners, and Belsay Loughs, Northumberland ; Boldon Plats, 

 Pardingslake, and Hardwicke, in the county of Durham ; Hilton 

 Pell, "Westmorland ; Lochmaben and Loch Skene, Dumfriesshire ; 

 Alemoor Loch, Selkirkshire, and in Connemara. 



The Alona reticulata of Schoedler should be carefully looked 

 for in Great Britain. While agreeing in the general characters 

 of the carapace with Z. testudinarius, the ventral line is not quite 

 straight, being slightly concave in the middle ; the head has more 

 the form of Z. quadrangularis, being less remarkably hood-shaped 

 than in Z. testudinarius, and the abdomen, instead of tapering to 

 the extremity, is distally widely truncate, and the claws have a 

 spine springing from their base. 



