122 THE JOURNAL OF EOTAXT 



olive colour. Otlier characters distinguishing C. cornea from C. laxa 

 are the well-marked collar at the base of the sporangium, similar to 

 that seen in Lamproderma arcyrionema (Rost.) and Clastoderma 

 Deharijamtm Blytt, and the free branches of the capillitium. The 

 specific name cornea refers to the translucent horn-colour of the 

 stalk. The description of Orfliotricliia Bacihorslcii Cel. fil. (Myxo- 

 m^'ceten Bolimens, p. 54) is applicable in some respects to the 

 present species, but the sporangia are said to be densely clustered, the 

 stcilks black, 0*5 to 0*6 mm. long, and the spores 10 to 11*5 /u diam. ; 

 the capillitium threads are described as not anastomosing, but in a 

 mounting of the type courteously lent by Dr. Celakovsk}'', although 

 the extremities of the threads are free, the branches anastomose 

 fi-equently elsewhere ; the gathering, a single one from near Prague, 

 appears to be a minute form of C. nigra. 



Comatricha fimbriata G. Lister & Cran, sp. n. Plasmodium 

 colourless. Sporangia scattered, stalked, globose, dark brown, 0*1 to 

 0*3 mm. diam. Stalks black, often inclined, very slender from a thicker 

 base, 0'007 to 0'02 mm. diam. above, 0*02 to 0-07 mm. at the base, 0*3 to 

 0*5 mm. long. Columella slender, cylindrical, truncate or tapering 

 above, reaching one third or one half the height of the sporangium. 

 Capillitium arising from the upper part and ajjex of the columella, 

 consisting of extremely slender ])ale purple-brown simple or sparingly 

 branched threads, darker and usually forked above and ending in 

 clavate or irregularly expanded tips. Spores 10 to 12 ^ diam., greyish- 

 purple, paler on one side, minutely and closely spinulose. 



Hahiiaf. On fallen sticks, Wanstead Pai'k, Essex, and Skene and 

 Hazelhead Wood near Aberdeen. C. fimbria fa was first obtained in 

 Wanstead Park, in November, 1913, by Mr. Raymond Finlayson. 

 The develo])ments consisted of about tliirty minute sporangia on a 

 dead bramble stem. In July 1916 Mr. Cran found it on a decorti- 

 cated elm-stick in Westhill Avenue, Skene, and also on a paling-post 

 lying among herbage in Hazelhead Wood. As soon as the spores 

 have fallen away, Avhich they do at the least breath, the sporangia with 

 their scanty capillitium and hair-like stalks are most shadowy objects. 

 The slender capillitium threads are often barely 1 /x diam. at the base ; 

 the flattened free ends measure from 2 to 5 ju diam. 'Wq lowei* part of 

 the stalk, when mounted, is seen to consist of a sheath of purplish-brown 

 anastomosing strands with slender connecting bars, enclosing a loose 

 network of paler strands. The specific wdmefiuihriafa, suggested by 

 Mr. Cran, refers to the fringe-like tuft of capillitium. It is not 

 surprising that this well-markecj but incons])icuous species should have 

 escaped detection beret; )f ore. 



Explanation of Plate 548. 



Fig. 1. Comatricha cornea G. Lister & Cran. Two sporangia with spores dis- 

 persed, on moss-leaf ; 1 a. large sporangium ; lb,lc. sjioi-angia showing 

 variety in capillitium ; 1 d. terminal branchlets of capillitium and three 

 spores ; 1 e. spore. 



Fig. 2. C. fimbriata G. Lister & Cran. Group of sporangia, one retaining spores ; 

 2 a. two sporangia showing capillitium ; 2 h. base of stalk showing loose 

 structure ; 2 r. capillitium thread with expanded tips and five spores ; 

 2 d. spore sliowing the smooth patch of dehiscence on one side of the wall. 



