Table 10
Distinguishing features of the three groups of Cuatro Ciénegas littoridinines.
| Group | Features |
|---|---|
| Paludiscala-Coahuilix | Animal blind, unpigmented; oviduct coils, gonopericardial ducts, seminal receptical absent ( fig 3c ); sperm duct (Sdu) connects bursa (Bu) and oviduct (Ov) at point where the latter enters the albumen gland (Ppo, fig 3c ); females oviparous; caecum of stomach greatly reduced; penis with apocrine gland (Fig 4c). |
| Mexithauma-Coachliopina | shell with strong sprial sculpture ( figs1f-h ); tentacles with hypertrophied ciliary tracts (fig 4): pallial oviduct with slight posterior bend ; seminal receptacle (Sr) opens directly into oviduct (Ov ); anterior end of brood pouch (Bp) strongly reflected and very muscularized; penis without specialized glands. |
| Mexipyrgus-Duragonella | shell elongate-conic to turriform ( figs 1d and e) ; pallial oviduct with posterior coil in several complex loops; albumen gland redcued to mere glandular smear; seminal receptacle (Sr) connects with oviduct (Ov) via a short sperm duct (Sdu, fig 3b ); anterior end of brood pouch (Bp) weakly reflected and slightly muscularized ( fig 3c ); penis with ciliated tip |
