277 



which become elongated and parallel where they form the ostiolum. The coni- 

 dial state of this fungus has been known in this county since the time of Sowerby, 

 but it was only in the month of September, 1880, that I was fortunate enough 

 to meet with perithecia. Several specimens were then found in Hockering Wood, 

 in company with the Rev. J. M. Du Port. Their development was carefully 

 watched by placing them, attached to the matrix (Russula nigricans), upon damp 

 sand under a bell glass. The conidia specially affect the pileus of the Nyctalis, 

 often so freely as to arrest the growth of the plant, and to cause it to assume the 

 appearance of an Onygena. The microconidia are produced by the tips of the hy- 

 ph», which break off in little cylindrical bodies. Lower dowTi upon the same 

 hyphae the macroconidia are produced often in great profusion. The lowest por- 

 tions of the hyphae are dilated and convoluted, and it is by an intertwining of 

 these convolute bases that the perithecia are produced, pi. 2d. As was the 

 case with Hypomyces chrysospermus, too free a production of macroconidia is 

 unfavourable to the development of perithecia. These are most frequently found 

 upon or inside the stem of the Nyctalis, but they are by no means of common 

 occurrence. 



Plate 2. a Nyctalis bearing the parasite. Nat. size. 

 b Macroconidia X 400. 

 c Microconidia X 400. 

 d Perithecium in formation X 400. 

 e Perithecium X 40. 

 y Perithecium X 400. 

 g Asci and sporidia (after Tulasne) X 400. 

 h Sporidia X 400. 



3. Hypomyces lateritius, Tul. Conidia minute, sphserical, colour- 

 less, -0035 to -007 mm. in diameter ; borne upon awl-shaped filaments, produced by 

 the thick web-Hke mycelium. 



Perithecia minute, ovato-globose, nestling in the white abundant mycelium; 

 apex smooth and slightly papillate, emergent. 



Asci cylindrical, scarcely attenuated below ; -2 to "25 mm. long by -006 to 

 •007 mm. wide. 



Sporidia eight ; uniseriate, uniseptate, acuminate, lanceolate, hyaline ; -015 

 to -02 mm. long by -0035 to -0045 mm. wide. 



Hypomyces lateritius, Tulasne. Sel. Fung. Carp, iii., p. 62, and n., p. 273, t. 30, 



f. 5. 



Ann. Sc. Nat., Ser. iv., 1860, p. 11. 



Fuckel Symb. My col., p. 182. 



Karsten Myc. Fenn. n., p. 211. 



Cooke Handbk., p. 779. 



Saccardo. Mich. p. 285. 



Plow. Exs., I., No. 5. 



Stevenson Myc. Scott., p. 359. 

 Merulius helvelloides. Sow., t. 402. 

 Hypolyssus ventricosus. Pers. Myc. Eur. ii., p. 7. 

 Agaric d^Iicieux, var. d^natur^. Secret. Myc. Helv. i., p. 567. 



