Bacillum theobaldi ( Hanley, 1870 )

Man, Nem Sian, Ablett, Jonathan D., Lwin, Ngwe, Sutcharit, Chirasak & Panha, Somsak, 2024, Contributions on a small collection of the former Subulinidae Fischer & Crosse, 1877 (Eupulmonata, Achatinoidea) with catalogue of the Glessula and Rishetia species recorded from Myanmar, ZooKeys 1208, pp. 173-239 : 173-239

3 Bacillum theobaldi ( Hanley, 1870)

Fig. 3 I

Achatina (Electra) theobaldi Hanley in Hanley and Theobald 1870: 9, pl. 17, fig. 5. Type locality: Near the Salwen [near Salween River, Myanmar].

Achatina (Glessula) theobaldiana [sic] — Theobald 1870: 395.

Achatina theobaldi — Pfeiffer 1876: 290.

Stenogyra (Glessula) theobaldiana — Nevill 1878: 172.

Stenogyra (Subulina) theobaldi — Pfeiffer and Clessin 1881: 327.

Bacillum theobaldi — Pilsbry 1906: 4, pl. 1, fig. 8. Gude 1914: 344, 345. Ramakrishna et al. 2010: 150.

Other material.

NHMUK 1912.4. 16.121 (1 shell; Fig. 3 G ) ex. Beddome collection from Burmah.

Diagnosis.

Shell elongate turreted and gradually attenuated; apex rounded, blunt and very large embryonic shell; subsequent whorls with strong and equally spaced radial ribs throughout. Aperture ovate; columella curved and truncated.

Distribution.

This species was recorded from near the Salween River and in Shan State, Myanmar ( Hanley and Theobald 1870; Pilsbry 1906). The additional report from ‘ India’ by Ramakrishna et al. (2010) is possibly erroneous.

Remarks.

No new material of this species was examined. Bacillum theobaldi was initially proposed without a proper description other than comparing it with B. cassiacum (Reeve, 1849 a) and with an imprecise type locality noted as ‘ Near the Salwen’ ( Hanley and Theobald 1870). Pilsbry (1906) confined the type locality as near to the Salween River in Shan State.

This species is superficially similar to B. obtusum in shell shape. However, B. theobaldi has equally spaced radial ridges (Fig. 3 I ), whereas B. obtusum processes finer radial striations (Fig. 3 H ).

Figures

Figure 3. A – D Allopeas gracile A lectotype NHMUK 1856.09. 15.68 / 1 from Mirzapore B paralectotypes NHMUK 1856.09. 15.68 / 2–11 and C, D specimen CUMZ 13066 from Mandalay Region, Myanmar with embryonic whorls and aperture E – H Bacillum obtusum E, F syntype NHMUK 1906.2. 2.349 from Bhamo, Upper Burmah G, H specimen NHMUK 1903.7. 1.1725 from Bhamo, Upper Burma and H juvenile shell with last whorl I Bacillum theobaldi, syntype NHMUK 1912.4. 16.121 from Burmah with last whorl.