210 THALLOPHYTA. [CH. 



Many forms of scale-insects and galls on leaves present an obvious 

 superficial resemblance to epiphyllous fungi, and might readily 

 be mistaken for the fructifications of certain Ascomycetous 

 species. As examples of scale-insects simulating fungi, reference 

 may be made to such genera of the Coccineae as Aspidiotus, 

 Diaspis, Lecanium, Coccus, and others. The female insects lying 

 on the surface of a leaf, if preserved as a fossil impression, might 

 easily be mistaken for perithecia\ 



Another pitfall in fossil mycology may be illustrated by a 

 description of a supposed fungus, Sclerotites Salisburiae^, Mass. 

 on a Tertiary Ginkgo leaf The figure given by Massalongo 

 represents a Ginkgo leaf with well marked veins, the lamina 

 between the veins being traversed by short discontinuous and 

 longitudinally-running lines; the latter are referred to as the 

 fungus. In a recent Ginkgo leaf one may easily detect with 

 the naked eye a number of short lines between and parallel 

 to the veins, which if examined in section are found to be 

 secretory canals. There can be little doubt that Sclerotites 

 Salishuriae owes its existence to the preservation of these 

 canals. 



The list of fossil fungi given by Meschinelli in Saccardo's 

 Sylloge Fungorum^ includes certain species which are of no 

 botanical value, and should have no place in any list which 

 claims to be authentic. 



Among the numerous examples of fossil 'fungi' which 

 have no claim to be classed with plants, there are some which 

 are in all probability the galleries of wood-eating animals. 

 The radiating grooves frequently found on the inner face of 

 the bark of a pine tree made by species of the beetle Bostrychus 

 might be mistaken for the impressions of the firm strands of 

 mycelial tissue of some Basidiomycetous fungus. 



In some notes on fossil fungi by J. F. James'' contributed 

 to the American Journal of Mycology in 1893, it is pointed 

 out that a supposed fungus described by Lesquereux from the 



1 For figures of the Coccineae, see Comstock (88), Maskell (87), Judeich and 

 Nitsche (95) &c. 



2 Massalongo (59) PI. i. fig. 1, p. 87. 



3 MeschineUi (92). ^ james, J. F. (932). 



