of the thallus nigro-punctatus, which can no longer be made a spe- 

 cific character. 1 In the way above described, many Gymnocarpi 

 are altered by anamorphosis, and vary according to the differences 

 of the genera, the fructification of which is affected. 



II. Cephalodia. These are monstrous Parmeliaceous apothecia, 

 wherein the thalamium bursts forth alone without any excipulum 

 thallodes, and is hence convex and subimmarginate. They are 

 nearly akin to the preceding, as is abundantly evident in the lichen 

 parasiticus already mentioned, when growing on Parmelia saxatilis ; 

 for here the black Verrucarioid dots of the latter are developed into 

 cephalodia on the former. Cephalodia are, then, abortive apothecia 

 of Parmeliese, personating the apothecia of Lecidinse. Where, as in 

 Usnea, the disk is normally much attenuated, the cephalodia appear 

 quite different; but where the contrary is the case, the cephalodia 

 nearly resemble the true apothecia. 



Another allied abnormal state of the apothecia is common in 

 Sticta pulmonacea ; this degeneration is accounted for by Fries, by 

 the disk's originating below the gonimous layer. 



III. Arihonia, that maculseform, oftener difform, immarginate 

 apothecium, wherein the excipulum and all the included parts are 

 confused ; on which Acharius founded his genus of the above 

 name. Eschweiler (Lich. in Mart. Fl. Bras. 1. c.), on the strength 

 of some Brazilian forms, hesitatingly restores the genus. Arthoniae 

 originate mostly from Opegrapha, but also, says Fries, from the Ver- 

 rucariese, and more rarely from the Lecidinse and lowest Parmeliece. 

 This anamorphosis depends upon station, and is not known to occur 

 in any but tree-lichens. The apothecia, nesting in the tender bark, 

 wherein they occur, are interrupted in their normal evolution by the 

 rapid growth of the matrix, and with the extension of the epider- 

 mis become dilated, until their interior parts are undistinguishahle. 



TV. Spiloma, that anamorphosis in which the apothecia are dis- 

 solved originally into heaps of granules, resembling naked spores. 

 From genuine lichens with a collapsed disk, this is further distin- 

 guished by the absence of any excipulum. Spilomata are produced 

 by too acute vicissitudes of climate, effecting the dissolution of the 

 apothecia. This may be by heat, whence those Spilomata peculiar 

 to warm countries, and wholly deficient at the North. Or it may 

 be by moisture and cold, when, sometimes, being less perfectly 

 evolved, they become floccose and approaching to nemata, when they 

 may be called viviparous apothecia. We see in this a revergence 

 of the anamorphosis of the apothecia to that of the hypothalhis, 

 from which last the degenerate state just described is with difficulty 

 distinguishable. So in Umbilicaria pustulata, it is matter of doubt 

 whether the byssaceous pulvinules occurring on it are to be referred 

 to abortive apothecia, or to prolifications of a degenerate hypothal- 

 line state of the thallus. 



1 In the third paper of the writer's Enumeration of N. E. lichens, a distinc- 

 tion was thus assumed for P. Halseyana there proposed, in its possessing these 

 black apophyses ; since Acharius had expressly denoted, as a distinction of P. 

 centrifuga, to which the plant afterwards proved to belong, that it wanted such 

 dots. They are indeed more commonly absent. 

 4 



