198 ENDOSPOEE^. [PERICH^NA. 



Hah. On dead wood and bark. — Epping Forest, Essex (L:B.M.164) ; 

 Lyme Eegis, Dorset ('L:B.M.164) ; Leicestershire (B. M. 696) ; Glamis, 

 Scotland (B. M. 323) ; Belgium (B. M. 690) ; Germany (B. M. 688) ; 

 Italy (B. M. 68.9) ; Poland (Strassb. Herb.) ; Australia (K. 153) : 

 Philadelphia (L:B.M.164; ; Ohio (L:B.M.164) ; S. Carolina (B. M. 

 697, 986). 



3. P. populina Fries, Symb. Gaster.,p. 12 (1817). Plasmodium 

 watery-grey, in decaying bark. Sporangia globose, depressed, 

 ellipsoid, or forming short broad plasmodiocarps, crowded, sessile 

 on a broad or narrow base, rarely substipitate, 0'5 to 1 mm. 

 diam., dark purple or purplish-brown, nut-brown, grey or white, 

 dehiscing along definite lines, either horizontally with a convex 

 lid or in broad sinuous lobes ; sporangium- wall of two layers, the 

 outer cartilaginous, opaque, charged with brown granular matter 

 intermixed with acicular or angvilar calcareous deposits which 

 form a pruinose or crystalline covering in the grey and white 

 sporangia ; inner layer membranous, usually closely combined 

 with the outer. Capillitium scanty or almost wanting, consisting 

 of slender, branched or simple, yellow threads, 1-5 to 4 /* diam., 

 irregularly compressed, angled and constricted, minutely warted, 

 rarely smooth ; attached to the sporangium-wall or free. Spores 

 yellow, more or less minutely warted, 12 to 14 /* diam. — 

 Lycoperdon corticate Batsch, Elench. Pung., p. 155 (1783). 

 PeriohcBna corticalis Rost., Mon., p. 293, fig. 188 ; Oooke, Myx. 

 Brit., p. 78 ; Zopf, in Schenk, Handbuch der Botanik, iii., 2, 

 p. 169; Blytt, Bidr. K. Norg., Sop. iii. (1892), p. 10; Macbride, 

 in Bull. ISTat. Hist. Iowa, ii., p. 120; Mass., Mon., p. 115. 

 Trichia fusco-atra Sibth., Fl. Oxon, p. 407 (1794). Ferichcena 

 fmco-atra Eost., Mon., p. 294 ; Oooke, Myx. Brit., p. 78. 

 Licea pannorum Oienk. (non Wallr.), Pringsh., Jahrb., iii., p. 407. 

 Ferichcena liceoides Rost., Mon., p. 295; Mass., Mon., p. 118. 

 Oligonema Broomei Mass., in Journ. R. Micr. Soc. (1889), 

 p. 346 ; Mass., Mon., p. 172. 



Plate LXXII., A. — a. sporangia, x 20 ; J. capillitium and portion of 

 sporangium-wall, x 280 ; c. capillitium and spore, x 600 (England). 



In large developments from one Plasmodium on the inner side of 

 the bark of old stumps, every variety of form is sometimes represented, 

 from broad plasmodiocarps to globose and substipitate sporangia, and 

 the colour rnay range from deep purple to grey. In gatherings where 

 the colour is pure white, the outer layer of the sporangiumrwall 

 consists of crystalline deposits of lime without the intermixture of 

 brown granules. The capillitium is subject to much variation according 

 to the season of the year and other causes. In a gathering at Lyme 

 Regis in the autumn, thfe capillitium was scanty, forming a net of 

 rugged coarsely warted threads 2 to 4 yu, diam., with a few scattered 

 free threads ; in the following spring another growth on the same 

 pieces of bark had sporangia of a similar shape and colour, but with 

 a more abundant capillitium forming a freely branching slender net- 

 work of minutely warted threads 1 to 1'5 fi. diam., scarcely difEering 

 from that of P. depri'ssa, the larger spores being the chief character 

 which distinguished the gathering from that species. The specimens 



