Table 2
Diagnotic features listed by Taylor (1966a) for hydrobiid subfamilies found in Cuatro Ciénegas
| Subfamily | Diagnostic features |
|---|---|
| Cochliopinae | Shell trochoid to planispiral |
| Littoridininae | Shell elongate to turriform; penis with bulbous or elongate lobes |
| Nymphphilinae | Shell large, trochoid, with operculum multispiral; penis with elongate filament and blood sinus; vas deferens in elevated ridge along mantle cavity floo |
| Mexithaumatinae | Shell with britsly periostracum; anterior end of pallial oviduct reflected; mantle edge papillate; tentacles with pigment strip along length |
| Paludiscalinae | Shell with lamelliform costae |