Among Pyrenolichens, Paratheliaceae, Mycoporaceae and Astrotheliaceae are almost exclusively of tropical distribution, and finally the leaf lichens with very few exceptions. These follow the leaf algae, _Mycoidea_, _Phycopeltis_, etc., which are so abundant on the coriaceous long-lived green leaves of a number of tropical Phanerogams. All the Strigulaceae are epiphytic lichens. _Phyllophthalmaria_ (Thelotremaceae) is also a leaf genus; one of the species, _Ph. coccinea_, has beautiful carmine-red apothecia. The genera of the tropical family Ectolechiaceae also inhabit leaves, but they are associated with Protococcaceae; one of the genera _Sporopodium_[1094] is remarkable as having hymenial gonidia. Though tropical in the main, epiphyllous lichens may spread to the regions beyond: _Sporopodium Caucasium_ and a sterile _Strigula_ were found by Elenkin and Woronichin[1095] on leaves of _Buxus sempervirens_ in the Caucasus, well outside the tropics. _Pilocarpon_, an epiphytic genus, is associated with Protococcaceae; one of the species, _P. leucoblepharum_, spreads from the bark to the leaves of pine-trees; it is widely distributed and has also been reported in the Caucasus[1096]. _Chrysothrix_, in which the gonidia belong to the algal genus _Palmella_, grows on Cactus spines in Chili, and may also rank as a subtropical epiphyllous lichen. A series of lichens from the warm temperate region of Transcaucasia investigated by Steiner[1097] were found to be very similar to those of Central Europe. Lecanoraceae were, however, more abundant than Lecideaceae and Verrucariaceae were comparatively rare. Much of Asia lies within tropical or subtropical influences. Several regions have received some amount of attention from collectors. From Persia there has been published a list of 59 species determined by Müller[1098]; several of them are Egyptian or Arabian plants, 15 are new species, but the greater number are European. A small collection of 53 species from India, near to Calcutta, published by Nylander[1099], included a new genus of Caliciaceae, _Pyrgidium_ (_P. bengalense_), allied to _Sphinctrina_. He also recorded _Ramalina angulosa_ in African species, along with _R. calicaris_, _R. farinacea_ and _Parmelia perlata_, f. _isidiophora_, which are British. Other foliose forms, _Physcia picta_, _Pyxine Cocoës_ and _P. Meissnerii_ are tropical or subtropical; along with these were collected crustaceous tropical species belonging to _Lecanorae_, _Lecideae_, Graphideae, etc. Leighton[1100] published a collection of Ceylon lichens and found that Graphideae predominated. Nylander[1101] came to the same conclusion with regard to lichens referred to him: out of 159 species investigated from Ceylon, there were 36 species of Graphideae. In another list[1102] of Labuan, Singapore and Malacca lichens, 164 in all, he found that 56 belonged to the Graphidei, 36 to Pyrenocarpei, 14 to Thelotremei and 11 to Parmelei; only 15 species were European.