44 ENBOSPORE^. [PHYSARUM. 



axils, lime-knots usually numerous, white, various in siiaps and 

 size, ' mostly large and angled. Spores violet-brown, _ almost 

 smootli, 7 to 10 /A diam. — Didymium melleum Berk. & Br., in Lmn. 

 Jour., xiv., p. 83 (1873). Physarum Schumacheri, var. ^ melleum 

 Rost.' Mon., App., p. 7. Didymium chrysopeplum Berk. & 

 Curt'.' in Grev., ii. (1873), p. 53. 



Plate IX., B. a. sporangia, and oae stalk showing a small columella, 



X 20 ; *. broken sporangia showing white capillitium, x 20 ; c. capilliti-am' 

 and fragment of sporangium- wall, x 280 ; d. spore, x 600 (United States). 



AUied to P. ciirinum, but constant in its characters ; of frequent 

 occurrence in the United States. 



Hab On dead wood, leaves, etc. — Cape (K. 57) ; Ceylon (B.M.4tl) ; 

 Borneo (K. 1257) ; Philadelphia (L:B.M. 18); Ohio (L:B.M.18) ; 

 Iowa (B.M. 1018) ; S. Carolina (B. M. 409, 853A). 



9. P. tenemm Rex, in Proc. Acad. Nat. Sc. Phil. 1890, p. 192. 

 Plasmodium? Total height, 1 to 2 mm. Sporangia globose, 

 stipitate, somewhat nodding, gregarious, yellow, 0'4 mm. diam. ; 

 sporangium-wall membranous with closely-set rounded thin clusters 

 of innate yellow granules. Stalk subulate, slender, opaque, 0'5 

 to 1"7 mm. long, pale yellow and filled with Hme above, darker 

 below from the presence of refuse matter. Columella none. 

 Capillitium of very delicate hyaline threads forming a regularly 

 meshed network, often persistent after the dispersion of the 

 spores, with numerous round or rounded yellow lime-knots, the 

 branches slender at the axils and mostly free from lime. Spores 

 violet-brown, nearly smooth, 7 to 8 //, diam. 



Plate X., A. — a. sporangia, x 20 ; b. stalk and capillitium, x 170 ; 

 V. capillitium and spores, x 280 ; d. spore, x 600 (United States). 



This species is closely allied to P. citrinum, differing in the more 

 slender form, in the delicate flexuose capillitium threads connecting 

 the lime-knots, and in the absence of a columella. ' Specimens sent by 

 Dr. Haviland from Borneo are similar to the type of Dr. Rex. A. 

 gathering from Mr. Morgan, Ohio, has small grey sporangia, 0'25 mm. 

 diam., rugose, with deposits of white lime-granules in the sporangium- 

 wall ; in other respects it is typical. 



Hob. On dead wood.— Borneo (L:B.M.19) ; New York (L:B.M.19) ; 

 Ohio (L;B.M.19). 



10. P. compactum Lister. Plasmodium? Total height 1 to 2 mm. 

 Sporangia globose or somewhat flattened below, O'B mm. diam., 

 stipitate, erect or nodding, spotted with pure white ; grey 

 or bronze colour and iridescent between the rounded spots ; 

 sporangium-wall membranous, with numerous well defined 

 rounded clusters of closely compacted lime granules. Stalk 

 erect or flexuose, subulate, furrowed, 0'5 to 1'5 mm. long., 0"05 to 

 0-13 thick at the base ; white and densely charged with lime 

 above, brown or black below from the presence of refuse matter ; 

 or white with chalky section to the base. Columella ^lone, or 

 represented by closely compacted lime-knots forming a globular 

 cluster 0-1 mm. diam. at the apex of the stalk, but lying free in the 



