Diadasia rinconis, subsp. opuntiœ, nov.—♀. About 15 millim long, varying to 13 millim.; tegulæ light reddish-brown, varying to darker; wing-nervures piceous, second submarginal cell variable, but always small and usually very narrow, and narrowed above; third submarginal cell long, very strongly elbowed at end; labrum with only a few scattered hairs, or sometimes more hairy; mesothorax strongly and quite densely punctured, much more so than in rinconis; scutellum closely punctured; abdominal bands as in rinconis, with curved anterior margins; hair at apex of abdomen yellowish fuscous.