Pterocyclos blandi Benson, 1851

Sutcharit, Chirasak, Tongkerd, Piyoros & Panha, Somsak, 2014, The land snail genus Pterocyclos Benson, 1832 (Caenogastropoda: Cyclophoridae) from Thailand and Peninsular Malaysia, with descriptions of two new species, Raffles Bulletin of Zoology 62, pp. 330-338 : 333

Pterocyclos blandi Benson, 1851

( Figs. 1 , 3E, F ; Table 1)

Pterocyclos blandi Benson, 1851: 196 , pl. 5 fig. 1. Type locality: Pulo Susson insulam prope Pulo Penang jacentem. Reeve, 1863: Pterocyclos , pl. 2 species 7. Morgan, 1885: 400. Kongim et al. 2013: 16, fig. 2B.

Pterocyclus blandi — Kobelt, 1902: 163. Laidlaw, 1928: 30. Maassen, 2001: 26.

Other material examined. Teluk Ewa , Pulau Langkawi, Kedah, Malaysia: CUMZ 3880 (64 shells), 4582 (44 shells, Fig. 3E, F ), 4583 (70 shells), 4584 (3 shells). Gua Cerita, Northern Island, Pulau Langkawi, Kedah, Malaysia: CUMZ 3879 (9 shells) .

Remark. Pterocyclos blandi was described by Benson (1851) in one of the two papers (out of nearly 60) in which Benson dealt with land snails and provided illustrations of specimens ( Naggs, 1997). The species identification is unambiguous and there are no type specimens. The species differs from all other Pterocyclos species by its depressed and thick shell, and transparent periostracum. The shell colour is usually uniform brown to purplish, rarely with variegated brown zigzag pattern, apertural lip whitish; upper part of the apertural lip broadly expanded and wing-shaped; lower part of the apertural lip thickened and not expanded. Accessory respiratory structure triangular, overhanging by the upper part of the apertural lip. Operculum calcareous, slightly concave inside, and multilamellae outside.

The species was not found in the limestone areas of Perlis, Kedah, Perak and Kelantan in Malaysia, and in southern Thailand. This suggests that P. blandi has a limited distribution and is possibly endemic to Langkawi Islands , Perlis, Malaysia, where the species seems to be declining due to exploitation of the limestone quarries .

Figures

Fig. 1. Distribution map of Pterocyclos species examined in this study. The numbered locality names are detailed in Table 1. The approximate type locality of Pterocyclos subalatus, and Pterocyclos umbraticus, are indicated by locality numbers 3 and 5, respectively.

Fig. 3. A–D, Shell and operculum of Pterocyclos rupestris: A, lectotype UMZC 2359.1; B, paralectotype UMZC 2359.2; C, syntype of var. 3 UMZC 2359.3; D, operculum from same lot of the paralectotype (showing top, side and bottom views). E, F, Specimens of P. blandi from Langkawi Island, Perlis, Malaysia CUMZ 4582. G, Holotype UMZC 1032 of P. subalatus. H–J, Pterocyclos spaleotes: H, lectotype NMW 1955.158.01107, I, paralectotype NMW 1981.118.02705; J, topotype specimen CUMZ 4585. K, Holotype ZMA Moll. 135622 of P. umbraticus. L–P, Pterocyclos diluvium Sutcharit & Panha, new species: L, holotype CUMZ 4595, M, paratype CUMZ 4588, N, specimen from Gua Cenderawasih, Perlis, Malaysia CUMZ 4592; and O, P, specimens from Tam Tone-din, Kuan-Don, Satun, Thailand CUMZ 4590 showing a: O, uniform whitish shell; and P, dark brown colour patterns. Q–S, Pterocyclos frednaggsi Sutcharit & Panha, new species: Q, holotype CUMZ 4594; R, paratype CUMZ 4581; S, specimen from Gua Pulai, Gua Musang, Kelantan, Malaysia CUMZ 4597.