Otf BOSMINID-E, MACROTHKICID^;, ETC. 385 



end of the rostrum. Eye-spot about half the size of the eye. 

 Abdomen of moderate length, inferior margin slightly arched, 

 superior nearly straight anteriorly, furnished with a conspicuous 

 blunt process, marginal teeth, from twelve to fourteen, sub-equal, 

 supero-posteal angle produced ; terminal claws rather short, gently 

 curved, having a secondary claw at the base, which is nearly half 

 the length of the primary claw. Length, -jVth f an inch. 



This species has been found in the following Northumberland 

 Loughs, Crag, Green Lea, Broomley, Chartners, Darden, and a 

 small pond on the moors near Winters Stob (A. M. N.) ; also in 

 North Shaws Loch, Selkirkshire ; Lochmaben, Dumfriesshire ; 

 Easedale Tarn and Thirlmere (Ox. S. B.) ; all these being in ele- 

 vated situations. 



On the Continent it is known to inhabit Norway, Sweden, and 

 Russia. 



1 1 . LyisrcEtrs acanthoceecoides, Fischer. PL XIX, fig. 5 ; 

 and PL XXI, fig. 7. 



1854. Lynceus acantliocercoides, Fischer. Bulletin de Soc. Imp. 

 des Natural, de Moscou, p. 431. PL III, figs. 21-25. 



1860. Lynceus quadrangular is, Leydig. Naturges. der Daphni- 

 den, p. 221. PL VIII, fig. 59. 



1860. Lynceus acantliocercoides, Leydig. Naturges. der Daph- 

 niden, p. 231. 



1863. Furycercus acantliocercoides, Schoedler. Neue Beitrage 

 der Naturgeschichte der Cladoceren, p. 11. 



1863. Alona Leydigii, Schoedler. Neue Beitrage der Naturg. 

 der Clad., p. 27. 



Carapace short, broad, nearly semicircular, well and regularly 

 arched from the extremity of the rostrum round the back and 

 thence to the infero-posteal angle, which angle is not furnished 

 with any spine ; the carapace posteriorly extends considerably 

 beyond the dorsal separation of the valves, the posterior extremity 

 being produced and rounded; ventral margin straight, ciliated, 

 cilia long ; surface longitudinally striate. Head of moderate size, 



