CHYDORLD^E. 107 



ALONELLA NAN A (Baird). 



1850. Acroperus nanus, Baird, p. 130, pi. xvi. fig. 6. 



1861. Aloiiapygmeea, G. 0. Sars, " Christiania ferekomrnende Clado- 



cerer," Vid.-Selsk. Forhand. Christiania, p. 20 (separate copy). 

 1863. Pleuroxus transrersus, Schodler, Neue Beitrage zur Naturgesch. 



d. Cladoceren, p. 50, pi. iii. tigs. 52, 53. 

 1867. Lynceus nanus, Norman & Brady, p. 396, pi. xviii. fig. 8, 



pi. xxi. fig. 8. 

 1900. Alonella nana, Lilljeborg, p. 517, pi. Ixxii. figs. 27-31. 



Small pond near Bennett's Cross, Dartmoor, in greater 

 abundance than \ve have ever seen it elsewhere ; canal near 

 Newton Abbott ; pond, Sandypark ; Broadmere Pond near 

 Chagford ; Torquay Reservoir ; River Otter ; Topsham 

 Marshes (A. M. N.}. 



PERACANTHA TRUNCATA (0. F. Miiller). 



1850. Peracantha tnmcata, Baird, p. 137, pi. xvi. fig. 1. 



1867. Lynceus truncntus, Norman & Brady, p. 387, pi. xxi. fig. 9. 



1900. Peratacantha truncata, Lilljeborg, p. 522, pi. Ixxiii. figs. 1-20. 



Lilljeborg has in his work substituted the more correct 

 form Peratacantha for Peracantlia, but such changes cannot 

 be allowed, for they would lead to endless confusion ; indeed, 

 it would be impossible to give a classical form to a large 

 proportion of generic names in use, and who cares about 

 the derivation and meaning of the mass of them. Like 

 Dick, Tom, or Harry, they represent to us living creatures 

 to which we apply the name, and with which we associate 

 the special characters. 



Exeter Canal, lake in Stover Park, Kingsteignton (A. 

 M. N.) ; pool near Mazarion (R. Vallentinl). 



PLEUROXUS TRIGONELLUS (0. F. Miiller). 



1863. Pleuroxus trigonellus, Schodler, Neue Beitrage zur Naturgescb, 



d. Cladoceren, p. 44, pi. ii. figs. 33-36. 

 1863. Pleuroxus ornatus, id. ibid. p. 47, pi. ii. fig. 32. 

 1874. Pleuroxus triyonellus, Kurz, Dodekas neuer Cladoceren &c., 



p. 189, pi. iii. figs. 2, 5. 

 1877. Pleuroxus trigonellus, Hellich, Die Cladoceren B6hniens r p. 103, 



tig. 60. 

 1888. Pleuroxus triyoncllus, Daday de Dees, Crust. Cladoeer. Faunae 



Hungaricse, p. 91, pi. i. tigs. 34, 35. 

 1900. Pleuroxus trigonellus, Lilljeborg, p. 534, pi. Ixxiv. figs. 13-23. 



Slapton Lea, Topsham Marshes (^1. J/. ^Y.). 

 PLEUROXUS UNCINATUS, Baird. 



1850. Pleuroxus uncinatus, Baird, p. 135, pi. xvii. fig. 4. 

 1863. Rhipophilus glaber, Schodler, Neue Beitrfige zur Naturgesch. 

 d. Cladoceren, p. 55, pi. iii. figs. 54-56. 



