MARGAEITA.] MAKGARITACE^. 203 



Capillitium of fasciculate threads, penicillate and slender above, 

 marked with spiral thickenings, attached above and below to 

 the sporangium-wall. (42) Peototeichia. 



Fig. hd.—Prototrichia JlagelUfera Eost. 



a. Group of sporangia. Magnified 4 times. 



J. Capillitium attached above to a fragment of 

 the sporangium-wall, and a spore. Mag- 

 nified 280 times. 



Fig. 60. 



Genus 40. — MARGARITA Lister, gen. nov. Sporangia globose; 

 capillitium a profuse web of coiled hair-hke, sparingly-branched, 

 slender, solid threads, with indistinct attachments to the 

 sporangium- wall. 



1. M. metallica Lister. Plasmodium watery-white, among 

 dead leaves and rotten wood. Sporangia globose, sessile on a 

 narrow base, 0'5 to 1 mm. diam., solitary or gregarious, pearl- 

 grey or copper-coloured, shining, iridescent ; sporangium-wall 

 single, somewhat tough, glaucous or yellowish, translucent. 

 Capillitium a profuse web of very long, even, soUd, grey or 

 yellowish threads, 0"5 to 1 /x diam., increasing in some parts to 

 2 /t, scarcely branching, with few attachments to the sporangium- 

 wall or apparently free. Spores pale yellow or nearly colourless, 

 minutely warted, 10 to 11 ft. diam. — Physarum metallicvmi Berk. 

 & Br., in Mag. Zool. and Bot., i., p. 49 (1838). Gornuvia metallica 

 Eost., Mon., App., p. 35 ; Cooke, Myx. Brit., p. 76. Perichcena 

 plasmodiocarpa Blytt, Bidr. K. Norg., Sop. iii. (1892), p. 10. 



Plate LXXIII., A. — a. sporangia, x 20 ; b. capillitium, showing the 

 bulbous end of a delicate thread adhering to a portion of the sporangium- 

 wall, and spores, a 280 ; c. capillitium and spore, x 600 (England). 



The capillitium is usually papillose on one side of the waved thread. 

 The spores vary in roughness from being distinctly warted to nearly 

 smooth. In gatherings from Lyme Regis, Dorset, and Wanstead, 

 Essex, the sporangia are scattered or crowded, pearly grey or iridescent 

 bronze ; those in Broome's collection, British Museum, are more or less 

 coppery. In specimens submitted by Prof. Blytt, of Christiania, they 

 are subglobose, and crowded with broad bases on a common hypothallus ; 

 the colour is bright copper, resembling some of Broome's specimens ; 

 the capillitium and spores are similar to those in the English gatherings. 

 This species has been removed from the genus Cornuvia on account of 

 the remote connection it holds with C. Serpula, which at present may 

 be considered the sole representative of that genus. The name Mar- 

 garita is given to the genus on account of the pearl-like appearance of 

 the sporangia. 



Hab. On dead leaves, sticks, etc. — Batheaston, Somerset (B. M. 94, 

 95, 98, 272) ; Wanstead, Essex (L:B.M.167) ; Lyme Regis, Dorset 

 (L:B.M.167); Birmingham (L:B.M.167) ; Norway (L:B.M.167). 



