Angulyagra Rao, 1931

Genus Angulyagra Rao, 1931 View in CoL

Dactylochlamys Rao, 1925: 132 View in CoL [non Dactylochlamys Lauterborn, 1901 View in CoL (Ciliophora), junior homonym].

Angulyagra Rao, 1931: 301 View in CoL .

Type species

Paludina oxytropis Benson, 1836 View in CoL , by original designation.

Diagnosis

“The shell is of large size, conical, thin but ornamented with prominent smooth spiral ridges which are concave on the internal surface. The base is somewhat flattened. The umbilicus is broadly rimate with a broad channel descending downwards from it. The mantle has enlarged and highly vascular finger-shaped processes on the margin” ( Rao 1925).

Remarks

The shell of Angulyagra is most similar to that of Torotaia or Dalipaludina , all of them possessing a large thin shell with strong keels, acute apex, and simple columellar lip. It can be distinguished from the latter two genera based on the following combination of characters: teleoconch whorls with strong keels obviously darker than the rest of the shell surface in colour, open umbilicus bordered by a strong keel; operculum with growth lamellae on exterior surface and radial striae on interior surface; radula with narrow marginal teeth, the width of both inner and outer marginal teeth is only half that of the lateral teeth, and outer marginal teeth with 15 tiny cusps; highly vascular finger-shaped processes on the mantle margin.