Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.
Paraproct: Paired, ventral extensions of the sternite on the last abdominal segment of some aquatic insects. The term is used more broadly to describe various appendages in the anal area of some other insects.
This other word references the same concept: paraprocts.