A new genus and species of stygobiontic dytiscid beetle, <I>Comaldessus stygius</I> (Coleoptera: Dytiscidae: Bidessini) from Comal Springs, Texas


  • Paul J. Spangler
  • Cheryl B. Barr


A new genus and species of stygobiontic bidessine dytiscid beetle, Comaldessus stygius, from Comal Springs, Texas, is described and compared with the proposed sister epigean genus Uvarus and the only other known stygobiontic bidessine water beetles, Trogloguignotus concii Sanfilippo from Venezuela and Uvarus chappuisi (Peschet) from Africa. Distinctive characters of the adult are illustrated with pen and ink drawings and scanning electron micrographs. The new taxon is the second stygobiontic bidessine genus with rudimentary eyes known from the Western Hemisphere and the first known from North America.