A new species of Ptychognathus Stimpson, 1858, from East and Southeast Asia, previously identified as Ptychognathus barbatus (A. Milne-Edwards, 1873) (Crustacea, Decapoda, Brachyura, Varunidae)

Three species of Ptychognathus. A, B. Ptychognathus barbatus (A. Milne-Edwards, 1873) (male, CW 10.2 mm, ZRC 2019.1806); C, D. Ptychognathus guijulugani Rathbun, 1914 (male, CW 8.8 mm, NCHUZOOL 17334); E, F. Ptychognathus pusillus Heller, 1865 (male, CW 13.2 mm, ZRC 2013.1844). A, C, E. Dorsal view; B, D, F. Ventral view.