Microcystina Penang sp. 5

Fig. 9 C

Material examined.

Malaysia • Penang Hill, Air Itam, Forest near Dam, Plot. 26; 5.3977 ° N, 100.2612 ° E; 290 m a. s. l.; 25 Oct. 2022; T. S. Liew, J. Dulipat leg.; BOR/MOL 15464 • Penang Hill, By Path H, Plot. 33; 5.4210 ° N, 100.2701 ° E; 610 m a. s. l.; 4 Feb. 2023; T. S. Liew, A. Yusni leg.; BOR/MOL 15762 .

Remarks.

This is a new record for Penang Hill. The shell spire is hardly raised, with a height less than half of the last whorl height. On the upper shell, there are densely spirally arranged pits on the apical and subsequent whorls. This species is unique among the Microcystina species from Penang Hill in having densely spirally arranged pits on the whorls near the periphery. Below the shell, there are densely spirally arranged pits that continue from the upper shell and fade away towards the umbilicus.