OF ARTS AND SCIENCES. 415 



contrast with the shorter, quite uniformly' thrice-septate spores of the 

 present. The spaces between the sporoblasts which represent dissepi- 

 ments in spores of this kind, are commonly (as in other species) not 

 quite straight. The sporoblasts are sometimes arranged more loosely, 

 with wider interspaces ; but no indication has appeared of a passage 

 into the spores of G. abstrusa. — The last-mentioned lichen appears 

 (by the citations of the German writers, the original description being 

 perhaps hardly sufficient) to have been first recognized as a species by 

 "Wallroth (Fl. Crypt. Germ. 1, p. 38), and, this being so, should bear 

 the name which he gave it. The fact that Acharius called the same 

 plant G. Wahlenhergiana, var. truncigena, can give no precedence to 

 the later specific name, Gyalecta or Lecidea truncigena, because the 

 Acharian designation expressly asserts the exact opposite to the latter, 

 namely, that the plant, instead of being a new, is an old species. And, 

 if this opinion is not mistaken, we may ventui-e to say generally, what 

 there are some reasons for saying, that the name which may happen to 

 be given to a variety has no precedence, but may be adopted, or not, 

 if the plant is taken up as a species. 



Gtalecta nana, sp. nov. : thallo tenuissimo leproso albido vel 

 obsolescente ; apotheciis minutissimis innato-emergentibus subplanis, ex- 

 cipulo pallido integro ab exteriore thallode lacero-dehiscente evanido 

 primitus velato discum carneo-fuscescentem cingente. Thecfe subcla- 

 vatse, 8 - 12-sporae. Sporaj parvul^, incolores, ex ellipsoideo dactyloidctC 

 vel subfusiformes, tetrablastse, diam. 3 - 5-plo longiores. Thallus ob- 

 scure or deficient. The very minute apothecia (scarcely more than 

 half the size of those of L. abstrusa) are flattish, with much the aspect 

 of those of G. carneo-lutea (Turn.), and similarly at first innate and 

 afterwards emergent ; the here entire, pale proper exciple being cov- 

 ered at first by a dehiscent and soon disappearing outer veil. Disk 

 pale brownish-flesh-colored, for the most part exceeded by the margin, 

 easily falling out, as in other species. . Paraphyses filiform, flexuous, the 

 summit thickened into a small head. Spore-sacks rather club-shaped, 

 commonly 10- 12-sporous, Spores small, colorless, from ellipsoid be- 

 coming dactyloid or subfusiform ; and from diblastish at length reg- 

 ularly tetrablastish ; for the most part four, more rarely five times 

 longer than wide. The similar spores of G. carneo-lutea (Herb. Borr. ; 

 "Welwitsch, Crypt. Lusit. n. 67) are at length regularly 6-blastish. 



Gtalecta ceratina, sp. nov.: thallo subobsoleto; apotheciis 

 minutis sessilibus concavis e fusco-rufo nigricantibus, margine subintegro 



