Pterocyclos umbraticus ( Benthem Jutting, 1949 )

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 : 335

Pterocyclos umbraticus ( Benthem Jutting, 1949)

( Figs. 1 , 3K )

Cyclotus umbraticus Benthem Jutting, 1949: 54 , 55, pl. 1 fig. 1. Type locality: Maxwell’s Hill (700 feet). Maassen, 2001: 15.

Type specimens. Holotype ZMA Mol. 135622 (height 13.2 × diameter 29.4 mm, Fig. 3K ) (no other material was available).

Remarks. Benthem Jutting (1949) described this species based on a number of shells. We have examined the holotype, which clearly does not show the typical characters of Cyclotus and, therefore, we suggest transferring the species to Pterocyclos . The shell has a relatively large, short channel-like accessory respiratory structure at the apertural lip, and the upper part of the apertural lip is expanded near the suture. In contrast, Cyclotus usually has a relatively small shell (diameter 10 – 30 mm), no accessory respiratory structure or only a short sutural tube, and has a corneous or thin calcareous, plate-shaped operculum ( Kobelt, 1902, 1911; Wenz, 1938). Because of these differences, we suggest the re-assignment of this species to Pterocyclos .

The characters by which P. umbraticus differs from the other Pterocyclos species are the chevron-shaped, zigzag sculpture on the upper shell surface, and the accessory respiratory structure that forms a nearly complete tube. In addition, this species tends to live in non-limestone forests of highland areas (altitude about 200 – 1600 m) in Pahang ( Benthem Jutting, 1949).

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.