144 EI7DOSPOREAE [STEMONITIS 



fasciculate. Stalk black, shining, 1 to 4 mm. lung, rising from 

 a well-developed brown membranous hypothallus. Columella 

 reaching to near the apex of the sporangium. Capillitium 

 of dark brown threads springing from all parts of the columella, 

 combined into a loose network, the ultimate brandies forming 

 a delicate superficial net, with angular, unequal meshes 

 varying from 6 to 16 /x wide. Spores grey or rufous-violet, 

 reticulated with rows of minute spines or with raised bands, 

 8 to 10 fi diam.— Rost. Mon., p. 193 ; Mass. Mon., 72, in 

 part. S. fasciculata Pers. Obs. Myc, 56 (1796). S. maxima 

 Schwein. in Trans. Amer. Phil. Soc, ser. 2, iv. 260 (1832) ; 

 Macbr. N. Am. Slime-Moulds, 116. S. dictyospora Rost. I.e., 

 p. 195 (1875) ; Mass. I.e., 83. S. nigrescens Rex in Proc. Acad. 

 Nat. Sci. Phil., 1891, 392; Macbr. I.e., 116. S. castillensis 

 Macbr. in Bull. Nat. Hist. Iowa, ii. 381 (1893). Clathrus 

 nudus L. Sp. PL, 1179 (1753) ? 



Var. 1. — rufescens Lister : spores faintly reticulated with 

 rows of minute spines, 5 to 8 /x diam. 



Var. 2. — trechispora Torrend : spores reticulated with 

 raised bands. — Torrend Fl. Myx., p. 141. 



Var. 3. — flaccida Lister : sporangia weak ; capillitium 

 scarcely forming a surface net. 



Var. 4. — confluens Lister : sporangia confluent, without 

 superficial net or columellae. — Amaurochaete speciosa Zukal 

 in Verh. Zool.-Bot. Gesell. Wien, xxxv. 335, t. 15, fig. 8. 



PI. 118.— a. b. sporangia (England) ; c. capillitium ; d. sporangia var. rufescens, 

 sporangium uniting the characters of the typical form and of var. rufescens ; i. three 

 e. capillitium of var. confluens ; /. spore ; g. spores, var. rufescens ; h. spores from one 

 spores trom one sporangium showing imperfect reticulation ; k. spores of var. trechi- 

 spora, from Venezuela, South Carolina and Japan respectively. 



This abundant species is the commonest form of Stemonitis in Em-ope 

 and North America. The spores are never smooth, and when magnified 

 1,000 diam. present the folio wing modifications in surface-markings; 

 these consist either of spines thickened and connected at their bases, 

 forming a complete net with from 20 to 50 meshes on the surface of the 

 hemisphere, and giving a continuous border to the spore ; or the spines 

 are less connected, forming a broken net, and giving an irregular border to 

 the spore ; or the spines are distinct, arranged on a more or less reticu- 

 late plan, giving a spinulose margin to the spore ; more rarely the spores 

 are marked with a complete net of raised bands without spines. In the 

 var. rufescens the sculpture is usually less pronounced, but the minute 

 spines are arranged in the same manner as in the typical form, giving 

 either a close or open reticulation to the surface of the spore (not evenly 

 distributed as in the faintly warted spores of S. splendens). These two 

 varieties represent well-marked centres, but there is no definite boundary 

 between them denoting a true specific difference ; sporangia widely 

 differing in length and with long or short stalks may have spores of 

 either form ; the var. confluens occurs with both large and small spores. 

 Rostafinski's specimens of S. fusca from Vera Cruz (B.M. 631) and from 



