ON BOSMINHLE, MACKOTHBICIB.2E, ' ETC. 365 



furnished with a spine at the base. The intestinal canal is coiled 

 upon itself in a large loop in the thorax. Length, -jVnd of an 

 inch. 



Gr. 0. Sars discovered this species in Sweden, in 1861. In 

 1864 it was met with by A. M. IS", in Darden Lough, North- 

 umberland, and shortly afterwards by Gr. S. B. in several other 

 localities, viz., Lochend Loch, Kirkcudbrightshire; Loch Skene, 

 and Lochmaben, Dumfriesshire ; Easedale Tarn and Bydal Lake, 

 Westmorland, and Lough Bollard, Connemara. 



Genus. LATHONURA, Lilljeborg. 



Carapace obovate, not produced centrally behind, dorsal margin 

 having a sinus at the junction of the thorax with the head, ven- 

 tral margin furnished with peculiar, flattened spear-shaped plates 

 attached to the edge. Anterior antenna? elongated, cylindrical, 

 dependent from the extremity of the rostrum. Posterior antenna? 

 having both rami furnished with five geniculate plumose seta?, 

 the basal seta of the three-jointed ramus not differing from the 

 others in structure. Eye-spot very minute, a mere speck. Abdo- 

 men very small, generally hidden between the feet, abdominal 

 seta? very long, not geniculate, but multiarticulate on the distal 

 portion. Intestinal canal simple. Living in clear lakes. 



LATHOinJEA eectzrosteis, (Miller.) PL XXIII, figs. 8-12. 



1785. Daphnia rectirostris, 0. P. Midler. Entomostraca, p. 92. 

 Tab. XII, fig. 1-3. 



1835. Pasithea rectirostris, Koch. Deutschlands Crustaceen, 

 Myriapoclen, &c, p. 35. PL XXIY. 



1844. Daphnia brachyura, Zaddach. Synopseos Crustaceorum 

 Prussicorum Prodromus, p. 23. 



1848. Pasithea brachyura, Lievin. Die Branchiopoden der Dan- 

 ziger GfegencL, p. 42. PL XI, figs. 1-3. 



1851. Daphnia mystacina, S. Pischer. Mem. presentes a 1' 

 Academie de St. Petersbourg. Vol. VI, p. 174. PL IV, 

 figs. 1-8. 



