110 ENDOSPOREAE [COLLODEEMA 



measure 14 to 16 /a diam. It is j)ossible that the spike-like processes 

 of the columella and inner sporangium-wall may not be an entirely 

 normai development ; irregular growths of D. lucidum occasionally 

 show similar though much shorter ingrowths from the sporangium- 

 wall associated with a columella having a lobed and rough surface. 

 Until further gatherings have been obtained confirming the distinctive 

 characters of the Ceylon specimen, it may be placed provisionally with 

 D. lucidum. 



Hab. On moss on wet rocks. — Trefriw, X. Wales (B.M. 25) ; Llany- 

 mawddwy (B.M. 1764). 



Genus 12.— COLLODERMA G. Lister in Journ. Bot., 

 xlviii. 312 (1910). Sporangia usually sessile ; sporangium- 

 wall consisting of two layers ; the outer gelatinous, with 

 superficial deposits of granular refuse-matter, and possibly 

 with additional deposits of minute lime-granules : the inner 

 layer membranous. Capillitium a network of purplish 

 threads without lime-knots. 



This genus appears to be allied to Diderma, but differs in having a 

 gelatinous outer layer to the sporangium-wall and in the deposits of lime 

 being scanty or absent. 



1. C. oculatum G. Lister, I.e. Plasmodium ? Sporangia 

 scattered or grouped in small clusters, sessile, rarely stalked, 

 either subglobose, 0*5 to 0-7 mm. diam., or forming short 

 plasmodiocarps, olive- or purplish-brown, glossy, sometimes 

 seated on a brownish-purple hypothallus ; sporangium-wall 

 of two layers ; the outer, when moist, thick, gelatinous, 

 byaline, more or less encrusted with yellowish- olive granular 

 refuse-matter ; the inner layer colourless, membranous, 

 firm. Stalk, when present, short, stout, dark brown. 

 Columella none. Capillitium branched and anastomosing to 

 form a network of pale or dark purplish-brown threads, colour- 

 less at the extremities, arising from the flat base of the 

 sporangium, 2 to 4 /x diam. below, becoming very slender 

 towards the surface. Spores brownish-purple, spinulose, 

 11 to 13 fj. diam. — Didymium oculatum Lippert in Verh. 

 Zool.-Bot. Gesell. Wien, xliv. 72, t. 4 (1894). 



This species was first observed by the late Christian Lippert, who 

 described it under the name of Didymium oculatum. It appeared on 

 old fir wood that had been brought from near Hallstadt, Upper Austria, 

 and kept for some months in a moist chamber. It has since been 

 obtained in Scotland by the Rev. W. Cran on hepatics and dead 

 coniferous wood, near Skene, Aberdeenshire, and also by Prof. 

 Farlow in New Hampshire. The young sporangia are at first dirty- 

 white, then bejonie yellow, and at length dark brown. When mature 

 and dry the sporangium-walls are brittle and dehisce irregularly. If 

 an unbroken sporangium be placed in water the outer gelatinous layer 

 of the wall swells and forms a hyaline investment O'l to 0'2 mm. thick, 

 completely surrounding the membranous inner layer with its enclosed 

 mass of spores and capillitium, and the " eye-like " effect is produced 



