126 ENDOSPORE^E. [LAMPRODERMA. 



a. genuinum : sporangia stalked. 

 ft. sessile : sporangia sessile. 



Plate XLVIL, B. a. sporangia, x 3 ; b. sporangia, a. genuinum, x 20 ; 

 c. coluTnella and capillitium, x 80 ; d. columellre of various shapes, from 

 one group of sporangia, x 20 ; e. sporangia, j3. sessile, x 20 ; /. capillitium of 

 same, x 80 ; g. spore, x 600 (England). 



The form sessile is represented by five separate gatherings. One from 

 the Pyrenees, on ffepaticce, is the type of Stemonitis iridescens Berk. (K. 

 1318) ; the sporangia, now broken, were globose, and either sessile or 

 on short stalks ; the capillitium is described by Rostafinski as colourless, 

 but in the sporangium examined, the few threads that remain are dark- 

 brown ; the columella is absent, but the base of the sporangium is 

 thickened by a tissue of interwoven bands ; the spores are purple-grey 

 as in the type of L. physaroides. The second gathering is from 

 Christiania, named L. columbinum, kindly furnished by Professor Blytt 

 (L:B.M.95); it is on moss in company with the long stalked form of 

 L. physaroides ; the globose sporangia are each seated on a horny base 

 of dried plasmodium ; there is no stalk or columella ; the capillitium 

 rises from the broad base of the sporangium and resembles that of the 

 stalked form ; the spores measure 16 to 19 /x ; in the accompanying 

 stipitate sporangia they measure 12 to 13 p.. Two other gatherings 

 are from near Leighton Buzzard, one on fir bark, the other on dead 

 leaves ; the sporangia are entirely without stalk or columella ; the 

 capillitium rises from the broad membranous base of the colourless 

 sporangium-wall, the threads are much branched and colourless at the 

 base, dark purple-brown, forked and anastomosing above ; the spores 

 are as in the type, 10 p. diam. The fifth is a gathering on fir bark by 

 Mr. Saunders, at Flitwick, Beds : the sporangia are dull-brown ; the 

 sporangium-wall pale amber, subcartilaginous, thickened at the base 

 by interwoven folds as in the specimen from the Pyrenees ; the 

 capillitium is abundant, of almost simple purple-brown threads, pale at 

 the points of attachment to the sporangium-wall ; the spores are of the 

 typical colour and roughness, 9 to 11 /A diam. The form genuinum of 

 this species is very constant in its main characters, yet it is met with in 

 the collections almost as frequently under the name of L. columbinum 

 as of L. physaroides. It is probable that both names were originally 

 given to the same species, and that Albertini and Schweinitz were not 

 acquainted with Persoon's type of Physarum columb'mum when they 

 gave the name of S. physaroides. The Strassburg collection does not 

 here assist us. There are three specimens in that collection marked as 

 Rostafinski's types of L. columbinum ; one is L. physaroides, one is 

 the pale form of L. violaceum, and the third is L. irideum. The type of 

 L. physaroides at Strassburg is the species described above in the 

 text, and the same 'as that supplied by de Bary to Professor Bay ley 

 Balfour under that name ; this nomenclature having become esta- 

 blished, L. columbinum is here placed as a synonym for L. physaroides. 



Hab. On fir-wood, moss, etc. a. Hanham, Gloucester (B.M. 204,205) ; 

 a. |8. Leighton, Beds (L:B.M.95) ; a. Moffat, Scotland (L:B.M.95) ; a. 

 France (K. 628) ; a. Germany (B M. 603, 604) ; /3. Pyrenees (K. 1318) ; 

 a. and |8. Norway (L:B.M 95) ; a. Mass., U.S.A. (L:B.M.95). 



2. L. echmulatum Eost., Mon., App., p. 25 (1876). Plas- 

 rnodium ? Total height 2 to 2 '5 mm. Sporangia globose, stipitate, 

 erect, gregarious, P 5 to 1 mm. diam., steel-blue, iridescent ; 

 sporangium-wall membranous, somewhat persistent, purplish or 



