Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 63. (Budapest 1971)

Gönczöl, J.: Aquatic Hyphomycetes from the Mts. Börzsöny

and the Soviet Union (ARNOLD, 1969). The few conidia found in the Morgó brook appeared in the sample from 9 April, 1970, taken at the middle reach of the stream, between the two sampling sites (as indicated also in the map). During the days preceding the collection the weather became very warm, subsequent to a cold, winter weather; the temperature of the brook increased to 6—8 °C against the 1—2 °C of the beginning of the month. The flood of the preceding days was passing, but the water deriving from the thawing snow on the higher parts of the mountains still kept the water level high. The conidia found were intact, not colourless but pale yellowish brown (such as found by NILSSON, 1962b). The four, distinctly septate cells were filled with a granular content, as in Actinospora megalospora ING., and Jaculispora submersa HUDSON & INGOLD. According to PETERSEN, this refers to C. gravida: "The spores of C. gravida contain dense, granular, refractile protoplasm". However, the dense, granular content of the cell did not continue into the appendages, they remained completely transparent. By its measurements, it could not be assigned to any one of the species constituting the genus Culicidospora. Its thickness exceeded the measurements given by PETERSEN for C. aquatica (9—11 [x instead of 12.8 u.), while the length of its axis considerably exceeded the 50 [x given for C. gravida in the key, attaining the lower value ascribed to C. aquatica (about 100 u.; an exact measuring was hindered by the position and curvature of the conidium). Dactylella aquatica (INGOLD) RANZONI (Table I, Figs. 6-9; Plate III, 8) Also one of the comparatively rare species. It was most frequent during the winter months, appearing in every sample from December till March. Its numbers gradually decreased beginning from April, and was hardly present in the summer months (none in June and July, and 2 conidia in a sample from August). On the other hand, I found strikingly much, even more than in the winter samples, at the upper reach (Sample site II) of the brook in June and August. The measurements of the conidia are rather constant; the longitudinal axis rarely exceeded 50 jx, the greatest width was about 20 jx. Conidia displaying a considerable variation of shape were found in the samples. Whole series of transitional forms pointed towards an unknown, clavate conidium on the one hand and to the aerial form of Margaritispora aquatica on the other. The aerial spore of Dactylella aquatica was about twice frequenter than the aquatic one. Flagellospora curvula INGOLD (Table II, Fig. 13) I found its conidia in every monthly sample of the year. No tendency in seasonal frequency could be established. It belongs to the medium frequent species (e.g. Anguillospora longissima and Heliscus lugdunensis in the greater part of the year); and greater quantities appeared on two occasions only: it represented 4—5% of all conidia in March, and 28%, a mass occurrence, in October.