24A ANALES DE LA SOCIEDAD CIENTÍFICA ARGENTINA 



Hab. Ad truncos humifusos putrescentes in syhis prope Guarapí, 



Maj.i880 (subnam. 3371). 

 Obs. Species pulcherrima ob pileum rigidulum atque stipitem 



subsuberosulum (si etiam in vivo) a genere AgaricoYi. nonnihil 

 ■ desciscens; sporidiis autem non visis sectione ergo dubia! 



4. Agarigus (Collybia)l aurantiellus Speg. (n. sp.) 



Diag. Coespitosus, rarius subsolitarius, inodoras; pileus convexo- 

 applanatus (1-4 cent, diam.), membranaceus, rigidulus, subpellii- 

 cidus (fere tremelloideus, in sicco, visus !), regularis v. plus 

 minusve excentricus, medio primo modicissime prominulas dein 

 depressus subumbilicatusque, margine laxe subinvoluto (in 

 sicco), tenui, acuto, integro, repandulo-undulato, centro fulve- 

 scenti- rubescens, ceterum aurantiacus v. rufescenti-aurantius, 

 laevis, glaber; lamellae trimacriae, laxiusculae, majores deorsum 

 latiusculae (1,5-2 mllm. lat.), tenui membranaceae, rigidulae, 

 acie integerriniae, antice attenuato-acutatae, postice rotundato- 

 sinuatae, denticuloque decurrentes, pileo concolores, laeves, 

 rugis transversis subconfertiusculis, centralibus majoribus 

 stricte lamelloideis, concoloribus conjunctae; stipes elongatus, 

 teres r. vix ad tertium inferum subinflatulus (3-7 cent, 

 long. — 3-4 mllm. crass.), rectus v. adscendenti-arcuatus (prae- 

 cipue et subabrupte basin versus), subcartilagineo-tenacellus, 

 late fistulosus, aurantius v. fulvescenti-aurantius, pubescentia 

 minuta, compacta, adpressa, ad tertium superum minute reticu- 

 latim rimoso-disjuncta, flavo-virescens, v. virescenti-fulvella 

 vestitus, basi tamen glabratus noduloseque adnato-coespitosus. 

 Basidia clavulata, utrinque obtusula, hyalina; sporae ellipticae, 

 deorsum lateraliter angulato-acutatae, byalinae (4-5 X 2-2,5). 



Hab. Ad truncos in sylva virgínea Caá-guazú vocata. Jan. 1882 

 (sub num. 3384.) 



Obs. Species eximia, habitu fere J^. /as«'cií/ans Huds., ad genus 

 Marasmius Fr. nec non Reliomyces Lev. nonihil vergens, ob 

 rugas transversas distinctissima, et facile novum genus! 



5. Agarigus (Collybiaj? hymeniigephalüs Speg. (n. sp.) 



Diag. Solitarius v. laxe gregarius, inodorus; pileus tenui-membra- 

 naceus, pellucidus, tenacellus, rigidulus (fere tremelloideus, in 

 sicco!), applanato-expansus (3-3,5 cent, diam.), orbicularis, cen- 

 tro non V. vix depressus, margine acuto, recto, regulari v. 



