ON BOSMINIBJ3, IklACItOTHKICID^:, ETC. 399 



angle ; those on the angle considerably longer than the rest ; 

 claws very long and slender ; the hinder edge is ciliated through- 

 out its entire length, and a very small spine springs from the 

 base. Length, -ryrd of an inch. 



Not common ; an inhabitant of lakes and large pieces of water. 

 Dr. Baird procured the type specimens near London, and met 

 with it in two or three places in that neighbourhood. We have 

 seen it from Crag Lough, in Northumberland (A. ~K. IS", and G. 

 S. B.), "Windermere, Grasmere, and Connemara (G. S. B.); and 

 the Paisley Canal (Mr. D. Robertson). On the Continent it is 

 known to inhabit Prussia, Norway, and Sweden. 



20. Lynceus sph^eeictts, Mailer. PI. XXI, fig. 12. 



1776. Lynceus sphcericus, Midler. Zool. Dan. Prod., No. 2392. 



1844. Lynceus sphcericus, Zaddach. Syn. Crust. Prussic. Prod., 

 p. 29. 



1848. Lynceus sphcericus, Lievin. Die Branchiopoden der Dan- 

 ziger Gegend, p. 41. PI. X, fig. 5. 



1850. Chydorus sphcericus, Baird. Brit. Entom., p. 126. PI. 



XYI, fig. 8. 



1851. Lynceus sphcericus, Pischer. Mem. presentes a 1' Acade- 



mie Iraper. des Scien. de St. Petersbourg par divers 

 Savans, Yol. YI, p. 192. PI. IX, figs. 13-15. 



1851. Lynceus sphcericus, $ Zenker. Midler's Archivs fur 

 Phys., &c, p. 119. PI. Ill, fig. 3. 



1853. Lynceus sphcericus, Lilljeborg. De Crust, ex Ord. tribus 

 Clad. Ostrac. et Copep., p. 86. PI. YII, figs. 12-17. 



i860. Lynceus sphcericus, Leydig. Naturges. der Daphniden, 

 p. 225. 



1863. Chydorus sphcericus, Schoedler. Neue Beitrage zur Na- 

 turges. der Cladoceren, p. 12. PI. I, figs. 5-7. 



Carapace nearly like that of the last species in form but very 

 much smaller, less regularly round, the posterior extremity being 

 slightly truncated; the rostrum not quite so long, the eye-spot 



