Key to subfamilies, tribes, subtribes, and genera of Ariidae

1a. Bones forming cephalic shield smooth or grooved; shape of vomerine tooth plates transversely elongate ...............................2

1b. Bones forming cephalic shield granulated; shape of vomerine tooth plates absent or not elongate …. Ariinae ......................3

2a. Posterior process of cleithrum connected by bony blade to second dorsal process of cleithrum; adipose-fin base longer than anal-fin base; maxillary barbel cylindrical; two pairs of mental barbels .............................. Galeichthyinae (genus Galeichthys)

2b. Posterior process of cleithrum free from second dorsal process of cleithrum; adipose-fin base shorter than one-half length of anal-fin base; maxillary barbel compressed; one pair of mental barbels ................................................. Bagreinae (genus Bagre)

3a. New World genera of Ariinae ...................................................................................................................................................................................... 4

3b. Old World genera and Subtribes of Ariini ............................................................................................................................................. 12