284 PROCEEDINGS OF THE AMERrCAN ACADEMY 



Nylander) to L. illecehrosa (which Acharius, Schcerer, and Nylander 

 have referred to Lecided) is fully considered ; these two species, not- 

 withstanding the divergence in shape of their apothecia, being nearer 

 to each other than to anything else. To these, L. hiformis (Floerk.), 

 Koerb., for a fine specimen of which I am indebted to Mr. v. Krem- 

 pelhuber, approaches near, and L. aUetina (Ach.), Koerb. chiefly differs 

 in its better-defined, larger apothecia, and rather larger spores. It is 

 with this last that L. premnea {Lecidea premnea, Ach. Lich. p. 173, 

 670. Nyl. Prodi-. Lich. Gall. p. 138, and Lich. Par. n. 67. Nyl. 

 Lich. Scand. p. 241. L. ahietina (Sm.), Hook., non Ach. Opegrapha 

 plocina, Koerb. Syst. Germ. p. 280. Pragmopora ? premnea, Koerb. 

 Pai-erg. p. 280), or the little group of which it is the type, is most 

 naturally associable. Long-forgotten and misunderstood, the well- 

 marked European member of this group was published at length, in 

 both the bark and the rock-forms, by Mr. Leighton and Dr. Nylander, 

 and its characters fully indicated in print. But it remained to observe 

 the varying expressions of the type in other, and especially the warmer 

 regions of the earth ; and Lecidea coniochlora, Mont. & Van den Bosch 

 (Lichenes Javanici, p. 37), scarcely differing from the European lichen 

 (to which it was referred in Nyl. Prodr. Lich. Gall.) except in its 

 longer spores, which are 8-12-locular, while the spores of the European 

 vary mostly from 4 to 6, was the first step, as it is still the most im- 

 portant one, in that direction. Lecidea insignior, Nyl. in Prodr. Fl. N. 

 Granat. 1. c. (Herb. Lindig. n. 2688) appears to be only a more marked 

 expression of this elongation of the spores, which was also indicated in 

 the earlier Lecidea premnea, v. plurilocularis, Nyl. Lich. N. Caled. 

 (Ann. Sci. 4. 15, p. 49) ; a phrase best agreeing, in its present limita- 

 tion, . with the described Java specimens, but not improbably to be 

 extended hereafter to cover the whole extent of the divergence. For 

 there is little else to distinguish these tropical forms. All agree, 

 generally, in their imperfect, or obsolescent thallus, and flattish, black, 

 greenish-pruinose apothecia, the prominent margin of which is pecu- 

 liarly "wrinkled" (Ach.) or "sub-erose" (Koerb.), with the Northern 

 type, and the blunt-fusiform or " oblong-fusiform " (Nyl.) outline of the 

 spores of the latter is traceable throughout. Lecidea proximata, Nyl. 

 in Prodr. Fl. N. Gran. 1. c. (the Lecanactis premnea of the present 

 writer in Lich. Cub. n. 243, where n. 244 is a form with more elongated 

 spores) is particularly observable for its better-developed thallus and 

 apothecia, the spores being rather intermediate (as is the case also in a 



