perichaena] arcyriaceae 251 



P.fusco-atra Rost. Mon., p. 294 (1875). P. Rostafinsicii Karst. 

 in Bidr. Kann. Finl. Nat., 1879, 130. P. microcarpa Schroet. 

 in Cohn Krypt. Fl. Schles., iii. pt. 1, 108 (1885) ? P. cano- 

 flavescens Raunk. in Bot. Tidssk., 1888, 54 ? P. nitens 

 Raunk. I.e., 55 ? Cornuvia dictyocarpa Krupa in Cosmos, 1886, 

 377 ? Oligonema Broomei Mass. in Journ. R. Micr. Soc, 1889, 

 346 ; Mass. Mon., 172. 



Var. 1. — affinis Lister: sporangia purple-red or red-brown, 

 dehiscing irregularly, granular deposits of outer sporangium- 

 wall often discontinuous ; capillitium forming a somewhat 

 abundant network of rather firm yellowish-brown threads, 

 2 to 3 fi diam. ; spores 10 to 12 fi. 



Var. 2. — liceoides Lister : sporangia subglobose or bolster- 

 shaped, nut-brown, minute, 0-2 to 0*5 mm. diam., dehiscing 

 irregularly ; granular deposits of outer sporangium-wall 

 scanty or wanting ; capillitium usually scanty ; spores 10 to 

 15 /a diam. — Perichaena liceoides Rost. Mon., p. 295 ; Mass. 

 Mon., 118. Licca pannorum Cienk. (non Wallr.) in Pringsh. 

 Jahrb. Bot., iii. 407 (1863). Lacknobolus pygmaeus Zukal in 

 Oester. Bot. Zeitschr., xliii. 136 (1893). 



PI. 186. — a. sporangia ; 6. capillitium and fragment of sporangium-wall ; c. capil- 

 litium and spore ; (England). 



This abundant and widely distributed species shows great variation 

 in the shape and colour of the sporangia, and in the abundance of the 

 capillitium. In large developments from one Plasmodium every 

 variety of form is sometimes represented from broad plasmodio carps to 

 globose and substipitato sporangia, and the colour may range from deep 

 purple to grey. In gatherings where the colour is pure white, the 

 sporangium-wall has an outer covering 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 made at Lyme Regis in the autumn, the capillitium was 

 scanty, forming a net of rugged coarsely warted threads 2 to 4 tt 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 brandling 

 slender network of minutely warted threads 1 to l - 5 /x diam., scarcely 

 differing from that of P. depressa, the larger spores being the chief 

 character which distinguished the gathering from that species. The 

 specimens named P. fusco-atra in the collections differ in no respect 

 from forms of P. corticalis, and cannot be held as specifically distinct. 

 The type of Oligonema Broomei Mass. from Warleigh (B.M. 364) is 

 typical P. corticalis witli characteristic branching capillitium threads 

 marked with irregular swellings and spinules, and with minutely and 

 closely warted spores 14 to 15 fx. diam. The var. affinis is a form having 

 the capillitium threads of firmer substance and forming a somewhat 

 abundant network. The spores are smaller than in the type. It 

 has been obtained from various parts of England and from Portugal. 

 The var. liceoides is a minute form, with translucent sporangium-wall 

 and weak capillitium. It is described by Cienkowski as Licea pannorum, 

 I.e., and is given by Rostafinski as the type of a new species, Perichaena 



