This paper considers whether Huxley's modification of the Wallace line represents a regional boundary affecting distribution in myxomycetes, using patterns of species composition from the territories of Borneo, Palawan, and the remainder of the Philippine archipelago. With a total of 30 species of myxomycetes belonging to 16 genera (taxonomic diversity index, TDI = 1.88), Borneo recorded the highest taxonomic diversity compared to Palawan with 56 species (TDI = 2.67) and the oceanic Philippines with 159 species (TDI = 4.18). Based on species composition, Borneo is more similar to Palawan (coefficient of community, CC = 0.395) than it is to the oceanic Philippines (0.254). However, Palawan is more similar to oceanic Philippines (0.502) than it is to Borneo. This suggests that Borneo and Palawan have a certain affinity in terms of species composition of myxomycetes, but Palawan still seems to have a higher community similarity to the remainder of the Philippine archipelago when compared to Borneo. Therefore, in terms of species composition alone, myxomycetes do not appear to concur with the biogeographic region delineated by Huxley's line.