Couplet 175

175a:  Prothorax with pleurosternal suture ending in a large, setose pit at anterolateral margin of fore coxal cavity; 2 basal ventrites connate; antenna with 11 antennomeres; 1.5-3.8 mm; deserts of U.S. West from Idaho to Mexican border (Cononotus)

Pyrochroidae   p. 440

175b:  Prothorax with or without pleurosternal suture, lacking large setose pit on anterior margin of fore coxal cavity; all ventrites usually free, or 2 basal ventrites connate (Aegialites); antenna with 10-11 antennomeres; length 1.5-7 mm; widespread in forests and Pacific beaches (Aegialites); if in deserts, antenna with 10 antennomeres (Dacoderus)