Key to genera of Central American Annulariidae

(excludes incertae sedis and species of doubtful occurrence)

1. Suture with fused tufts...................................................................... Choanopomops

- Suture serrate but individual axial elements are unfused....................................................... 2

2. Operculum a paucispiral, chondroid (horny) plate without calcareous raised lamellae or a plate, but may have a granular deposit................................................................................... Parachondria

- Operculum with calcareous, raised lamellae or plate.......................................................... 3

3. Shell turbinoid, height and length approximately equal, operculum a flat, nearly smooth plate.................. Tudorisca

- Shell conic, more elongate, operculum not a smooth plate..................................................... 4

4. Operculum modified paucispiral, with a wide, perpendicularly reflected calcareous deposit composed of numerous distally unfused spiraling lamellae..................................................................... Halotudora

- Operculum multispiral, with lamellae wholly fused into a single narrow, somewhat reflected calcareous lamella.......... 5

5. Adult peristome scarcely apparent and barely reflected, whorls angled................................. Paradoxipoma

- Adult peristome obviously apparent and reflected, whorls rounded.............................................. 6

6. Final whorl attached or narrowly separated from previous whorl...................................... Gouldipoma

- Final whorl obviously separated from previous whorl................................................ Diplopoma