Mathilda, Semper, 1865

Szabó, János & Jaitly, Anand Kumar, 2019, Additional Middle Jurassic gastropods from Kachchh (western India) in the collections of the Banaras Hindu University (Varanasi, India), Fragmenta Palaeontologica Hungarica 36, pp. 3-30 : 28

Mathilda ? sp.

( Fig. 79 )

Material – Single, fragmentary specimen.

Measurements – Inv. No.: BHU 2020I 311; H dam. = 3.5 mm, D = 1.8 mm.

Description – Minute, turriculate shell without apical and latest shell parts. The shape of the preserved whorls is quite characteristic; they have a wide, slightly convex subsutural ramp, abaxially limited by a nearly mid-whorl angulation; the remaining part of the whorls actually also form ramp that slopes adaxially towards the lower suture.

The angulation between the ramps bears a carina, further double spiral threads are above and below it; no more ornament, neither growth lines are preserved.

Remarks – The shell is characteristic enough to place it in Mathildidae but poorly preserved for accurate identification.

Occurrence – Fakirwari, Chari Formation, Callovian.

Figures

Figs 67–83. Further caenogastropods and some acteonoideans. – Figs 67–74. Two deformed specimens of Diarthema sp. – 67–70. BHU2020I 306 specimen in apical, flattened apertural, abapertural views, and an image parallel to the compressed aperture, ×3.9. – 71–74. BHU2029I 307 specimen in apical,“apertural”, “abapertural”, and in peristome planeviews,×4.2.– Fig. 75. Cuphotifer? sp., the only informative view, ×10. – Figs 76–77. Purpurina sp. in apertural and abapertural positions, ×2.8. – Fig. 78. Parvulactaeon? sp., the most informative view, ×7. – Fig. 79. Mathilda? sp. on loose matrix surface, ×8.7. – Figs 80–83. Sulcoacteon haboensis n. sp., holotype. – 80–82. Apertural, abapertural and apical views; oblique apertural view, ×7.3. – 83. Inner face of columellar lip, bearing also vertical fissure of umbilicus, ×7.3; Fig. 80 shows outline of the entire, very thin outer lip and the shape of the aperture. This outer lip suffered subsequently damages (Fig. 83) dur- ing the cleaning of the inner lip region, bearing diagnostic characters