PER CENT OF GRAVID GILLS WITHOUT MITES OR PAPILLAE PER CENT GRAVID 
113 
1951 3 Humes and Russell — Najadicola ingens 
GRAPH I. BOTTOM TEMPERATURE AND THICKNESS OF ICE IN WASH POND. 
GRAPH 2. MONTHLY OCCURRENCE OF GRAVID A. CATARACTA AND E. COMPLANATUS . 
= GILLS COMPLETELY GRAVID 
= GILLS PARTIALLY GRAVID 
GRAPH 3. MONTHLY OCCURRENCE OF COMPLETELY AND PARTIALLY GRAVID GILLS IN 
UNPARASITIZED A. CATARACTA . 
THICKNESS OF ICE fN INCHES 
