LEPIDODERMA.] DIDYMIACE.E. 107 



nodules, separating more or less from the membranous, pale-brown 

 inner layer. The columella is hemispherical or hardly evident, brown, 

 of spongy texture within, densely charged with rounded nodules of 

 lime ; the capillitium is a network of pale-brown, hyaline threads, 

 with numerous wide membranous expansions, containing scanty 

 deposits of lime in the form of rounded nodules 20 to 30 p. diam. ; the 

 spores are purplish-black, closely spinulose, 15 to 30 ^ diam. The 

 cartilaginous sporangium-wall, with its crystalline deposits of lime 

 and the structure of the columella, appears to mark this species, which 

 is represented by a solitary gathering, as a Lepidoderma. Although 

 lime does not occur in well-developed capillitium of the Didt/miacece, 

 it is occasionally found in nodular deposits in the threads ofDidymium 

 squarmdosum said D. farinaceum. It is possible, from its presence in 

 the capillitium of Dr. Harkness' gathering, that this is not a perfect 

 development, and this view is supported by the great variety in the 

 size of the spores. 



Plate XLIL, A. a. sporangia, x 20 ; b. capillitium and spores, with 

 fragment of sporangium-wall, x 280 (California). 



SPECIES NOT MET WITH IX THE QUOTED COLLECTIONS. 



3. L. Chailletii Host., Mon., p. 189, fig. 179. Sporangia hemi- 

 spherical, adnate on a broad base to the hypothallus or substratum, 

 violet-black, covered with many pearl- like, brown, protuberances ; 

 columella small, brownish- ochre ; capillitium of dull-violet threads 

 forming a dense net ; spores dull violet, warted, 10'8 to 12'5 (JL 

 diam. 



Hal). Switzerland (Chaillet) ; Hammerstein (Opiz). The columella 

 is composed of fibres forming numerous false chambers filled with 

 crystalline nodules of lime. 



This description applies to a sessile form of L. t'ujriiuun. 



4. L. obovatum Mass., Mon., p. 254. Sporangia broadly 

 obovate, stipitate ; wall dirty ochraceous, thick, studded with 

 large innate patches of lime ; stem short, thick, dark brown, 

 wrinkled ; colum* lla none ; threads of capillitium 3 to 4 /x thick, 

 dingy violet, branching dichotomously with a swelling at the base 

 of each branch, the whole combined into an irregular net ; spores 

 clingy violet, minutely warted, 11 to 13 /x diam. 



Hal. On grass and twigs. Sweden ; Kew Herb. 



I have seen no specimen thus named in Kew Herb. The figures 

 (45 47) are given by Massee in the text of his Monograph as repre- 

 senting this species, but they refer to other species for which they are 

 elsewhere quoted. 



The description of L. Kurzii Berk. (Mass., Mon., p. 255), taken from 

 the MS. in Berkeley's Herb., has no mention made of the capillitium, 

 and is too brief to be instructive. 



SPECIES EXCLUDED FROM THE GENUS. 



L. reticidatum Mass. = Badhamia decipiens Berk. 

 L. stellatum Mass. = Physarum compactum List. 



