The taxon Platysma thomsotiii Stirton is transferred to the new genus Parmelaria Awas., and a new species Parmelaria subthomsonii Awas. is described. Platysma thomsonii Stirton was apparently named by Stirton (1879) after J. A. Thomson as is clear from the remark after the protologue, “The two preceding spe cies are from a fine collection of foliaceous lichens in the possession of Mr. J. A. Thomson of this city, who secured them several years ago from the Himalayas near Darjeeling”, the two preceding species being Platysma thomsonii and Physcia incana Stirton. A specimen annotated as Type of Platysma thomsonii Stirton and collected by J.A.ThomsonNo.36ispreservedatglam (No.NHB-1927-8-1643)andisundoubtedly the holotype. At g l a m there are 3 other specimens collected by G. W att from Sikkim, Sandakfu and Lingalelah Range in 1881 and numbered 5311, 5315 and 7065 re spectively. They are also annotated as Platysma thomsonii Stirton. There are no dup licates of any of the above at BM. The specimen referred to by Culberson (1962: 306- 07) at G, may possibly be a duplicate of the above mentioned G. Watt collections.