107 R. F. CASTAN  EDA RUIZ 1 , T. ITURRIAGA 2 AND C. DECOCK 3  Instituto de Investigaciones Fundamentales en Agricultura Tropical Alejandro de Humboldt,(INIFAT), calle 1 esq. 2, Santiago de Las Vegas, Ciudad de La Habana, Cuba C.P. 17200  Departamento de Biologia de Organismos, Universidad Simon Bolivar, Sartenejas, Baruta, Edo Miranda, C.P. 89000, Venezuela  Mycothe  que de l’Universite  catholique de Louvain (BCCMMUCL, MBLA), Place Croix du Sud, 3, 1348 Louvain-la-Neuve, Belgium Bulbocatenospora complanata gen. et sp. nov. is described and illustrated. The fungus is characterized by the production of inconspicuous, brown conidiophores, usually reduced to the conidiogenous cells, which are monotretic, ventricose, dark brown, with a well-defined pore. The conidia are muriform, broadly ovoid to irregular, complanate, brown, forming short, acropetal chains. The fungus was found on rotten leaves of Bactris setulosa in an undisturbed rainforest in Venezuela. Comparisons are made with some morphologically similar genera, Piricauda, Chuppia and Janetia. During a mycological survey of saprobic conidial fungi from tropical leaf litter in an undisturbed rainforest in Venezuela, an unknown dematiaceous hyphomycete forming short, acropetal chains of brown, muriform, complanate conidia was found on a decaying leaf of the palm Bactris setulosa Oerst. The conidia are borne from a little differentiated, intercalary, brown conidiogenous cell, leaving a well-defined pore after secession. None of the existing genera of hyphomycetes has such a combination of characters and a new genus, Bulbocatenospora, is proposed. MATERIALS AND METHODS The fungus was isolated from single conidia captured under a stereo microscope immediately after they were collected from the substrate. It was grown on corn meal agar, mixed 1 : 1 with carrot extract, and at 25 C under alternating cycles of 12 h of day light and darkness. Mounts were prepared in lactophenol cotton-blue and measurements made at 1000 magnification. TAXONOMY Bulbocatenospora R. F. Castan  eda & Iturr., gen. nov. Ad fungos conidiales, hyphomycetes pertinens. Coloniae in substrato naturali effusae, nigrae. Mycelium partim superficiale et partim in substrato immersum. Conidiophora inconspicua in cellula conidiogena reducta. Cellulae conidiogenae monotreticae, determinatae, intercalares, cum poro manifesto praeditae. Conidiorum secessio schizolytica. Conidia muriformia, ovoidea, triangularia usque ad irregularia, complanata cum cellulis bulbosis praedita atrobrunnea vel brunnea ; blastocatenata, non ramosa. Species typica : Bulbocatenospora complanata. Etym. : bulbo-, refers to the bulb-like cells ; cateno-, formed in a chain ; spora, spores. Conidial fungi, hyphomycetes, Colonies on natural substrate effuse, black. Conidiophores inconspicuous, mostly reduced to conidiogenous cells. Conidiogenous cells monotretic, deter- minate, intercalary, with a well-defined pore. Conidial secession schizolytic. Conidia muriform, ovoid, triangular to irregular, complanate, with bulbous cells, dark brown to brown, formed in unbranched, acropetal chains. Type species : Bulbocatenospora complanata anam. sp. nov. Bulbocatenospora complanata R. F. Castan  eda, Iturr. & C. Decock, sp. nov. (Figs 1–7) Ad fungos conidiales, hyphomycetes pertinens. Coloniae in substrato naturali effusae, nigrae. Mycelium plerumque in substrato immersum, ex hyphis septatis, ramosis, laevibus, dilute brunneis usque brunneis, 2–35 μm diam. compositum. Conidiophora inconspicua in cellula conidiogena reducta. Cellulae conidiogenae monotreticae, ventricosae, 10–1445–55 μm, determinatae, intercalares, atro-brunneae, cum poro manifesto, 15–25 μm diam. praeditae. Conidiorum secessio schizolytica. Conidia muriformia, 16–2912–16 μm, ovoidea, tri- angularia usque ad irregularia, complanata, blastocatenata, non- ramosa, atrobrunnea vel brunnea cum 4–7 seriebus horizontalibus cellulis bulbosis, 3–5 μm diam., brunneis, laevibus, praedita ; sed cellula apicalis hemisphaerica, 3–45–6 μm ; pori 1–25 μm diam. in cellulis apicalibus et basilibus adsunt. Teleomorphosis ignota. Holotypus : In foliis dejectis Bactris setulosae, Camino de Interpretacio  n de la Naturaleza Andy Fields, alt. 1200 m, Estacio  n Rancho Grande, Parque Nacional Henry Pitier, Estado de Aragua, Venezuela, Legit R. F. Castan  eda et T. Iturriaga, 25 Nov. 1997, in herbario MUCL (MUCL 40705). Etym. : complanata, complanate. Conidial fungi, Hyphomycetes. Colonies on the natural substratum effuse, black. Mycelium mostly immersed. Hyphae Mycol. Res. 104 (1) : 107–109 (2000) Printed in the United Kingdom Bulbocatenospora, a new hyphomycete genus from Venezuela