266 



SIG THOR: PRODROMUS SYSTEM. HYDRACHN1D. 



Genera: 51. Encentridophorus Piersig (1897). 



52. Atax Fabricius (1805), Bruzelius (1854) 

 = Najadicola Piersig (1897) = Unio- 

 nicola Haldeman (1842). 



XII. Familia: Brachypodidae Sig Thor (1900). 



Genera: 53. Brachypoda Lebert (1875) = Axona 

 Kramer (1875). 



54. Axonopsis Piersig (1893). 



55. Ljomia Sig Thor. (1898). 



XIII. Familia: 



Genera : 



Aturidae Sig Thor (1900). 



56. Aturus Kramer (1875). 



57. Kongsbergia Sig Thor (1899). 



58. Albia K. Thon (1899). 



59. Feltria Koenike (1892). 



60. Koenikea Wolcott (1900). 



61. Tanaognathus Wolcott (1900). 



62. Ecpolus Koenike (1898). 



XIV. Familia: 



Genera : 



Arrenuridae Sig Thor (1900). 



63. Arrenurus Duges (1834) = Anurania 

 Neuman (1880). 

 Subgenus: Megalurus K. Thon (1900). 

 Subgenus: Micrtirus K. Thon (1900). 

 Petiolurus K. Thon (1900). 



a. 

 b. 

 c. 



Subgenus: 



Ghristianiæ 2 Sept. 1900. 



