270 ANALES DE LA SOCIEDAD CIENTÍFICA ARGENTINA 



Species hac nec non omnes sequentes mihi difficillimae ad determi- 

 nandum fuerunt, ob diagnoses numerosissimas saepeqne imper- 

 fectissimas hujus generis,et in plurimis perdubiosus adhuc maneo. 



193. Hypoxylon plumbeum Speg. (n. sp.) 



Diag. Eubypoxylon: stromata matrice subpulverulento-nigrefacta 

 insidentia, discoideo-repanda ac convexo-pulvinata (3-6 millim. 

 diam.=::l-2 mllm crass.), margine determinata non v. vix sub- 

 coarctata, sparsa v, aggregata saepeque conñuentia, dense mam- 

 millosa, fere rubiformia, extas primo pruinula subcrustacea, 

 non detersili, plúmbeo- v. argenteo-grisea vestita, dein nuda, 

 atra, intus fusco-rubiginosa v. fusco-atra; perithecia 10-50- ag- 

 gregata, ad tertium supernm tantum prominulo-hemisphaerica, 

 laevissima, ostiolo minutissimo, imperspicuo non papillato do- 

 nata; asci cylindracei, modice stipitati (100-110 X 6-6. 5), api- 

 ce subtruncato-rotundati, octospori, paraphysibus densis, ñli- 

 "formibus obvallati; sporae recte v. oblique monosticbae, ellipti- 

 cae V. elliptico-naviculares, utrinque acutato-obtusatae (10 - 12 

 x5-6), 1 V. 2-guttiiIatae, opace fuligineae. 



Hab. Ad ligna cariosa putrescentia in nemorosis prope Guarapí, 

 2 Aug. 1881 (sub num. 2760). 



Obs. Species praecedenti affinis, sed peritheciis majoribus distinc- 

 tissima. 



19-4. Hypoxylon crustaceüm (Sow.) Nitz.= S'acc. Syll. Tung. I, 

 n. 1463. 



Hab. Ad truncos dejectos putrescentes in sylvis prope Guarapi, 

 29 Julio 1881 (sub num. 2762). 



Obs. Placoxylon : stromata pulvinato-effusa (10-20 cent. lat.=0. 7- 

 1 mllm. crass.), superficialia, ligno denudato ac nigricante insi- 

 dentia, primo velo pruinuloso tenuissimo fusco-plnmbeo vestita, 

 dein nuda, atra, opaca, dense granulosa; perithecia globosa 

 (450-550 diam.) e mutua pressione angulosa, vix rotundato- 

 prominula, atra, carbonacea, ostiolo papillato, minute exerto 

 gerentia ; sporae elliptico-naviculares, utrinque obtusiusculae 

 (8-10x4-5), opace fuligineae. 



Specimina guaranitica a typo peritheciis conspicue minoribus re- 

 cedunt. An eadem species ? 



195. Hypoxylon crocatum Mntg. = Sacc. Syll. Fung. I, n. 1438, 



