The Collaborative International Dictionary of English v.0.48:

Paludal \Pa*lu"dal\, a. [L. palus, -udis, a marsh.]
   Of or pertaining to marshes or fens; marshy. [R.]
   [1913 Webster]

   Paludal fever, malarial fever; -- so called because
      generated in marshy districts.
      [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

18 Moby Thesaurus words for "paludal":
   boggish, boggy, fenny, marish, marshy, mirish, miry, moorish,
   moory, muddy, paludous, poachy, quaggy, quagmiry, spouty, swampish,
   swampy, uliginous