234 ENDOSPOREAE [ARCYRIA 



1. A. ferruginea Sauter in Flora, xxiv. 316 (1841). 

 Plasmodium rose-red or cream-coloured. Total height 

 1 to 2 mm. Sporangia stalked, crowded, ovoid, 0-7 to 1*3 mm. 

 high, 0-5 to 1 mm. broad, orange-red or red. more rarely 

 ochraceous or yellow ; cup of sporangium even, shining, 

 funnel-shaped, or at length nearly flat, marked with round- 

 meshed reticulation on the inner side. Stalk cylindrical, 

 0-3 to 0-8 mm. long, 0-05 to 0-15 mm. thick, red, rarely white, 

 arising from a well-developed membranous hypothallus, filled 

 with spore-like cells. Capillitium an elastic network of freely 

 branching reddish-yellow or yellow threads, 5 to 6 ti diam., 

 diminishing to 2 to 3 jx diam. towards the base, triangular or 

 oval in section, usually thicker on one side and marked with 

 transverse bars or reticulations arranged in a lax spiral, on the 

 other two sides marked with a broken reticulation or with 

 warts, often spinulose throughout ; a few sparingly branched, 

 more slender and smoother threads penetrate the tube of the 

 stalk, but are not attached to the cup ; free ends with 

 rounded or pointed tips are not unfrequent. Spores pale red 

 or ochraceous, faintly and closely warted, 8 to 11 /x diam. — 

 Rost. Mon.,p. 279 ; Mass. Mon., 144 ; Macbr. N. Am. Slime- 

 Moulds, 194 ; Petch in Ann. Perad., iv. 365. A. dictyonema 

 Rost. I.e. ; Mass. I.e., 154. A. intricata Rost. I.e., App. p. 37 

 (1876). A. cinnamonea Hazsl. inOester. Bot.Zeitschr., xxvii. 

 84 (1877). A. bonariensis Speg. in Ann. Soc. Cient. Argent., x. 

 151(1880)? A.macrospora Peck in Rep. N. York State Mus., 

 xxxiv. 43 (1881). A. inermis Racib. in Rozpr. Mat. Przyr. 

 Ak. Krak., xii. 82 (1884). A. decipiens Racib. I.e., 84 ? 

 A. aurantiaca Raunk. in Bot. Tidssk., 1888, 61, t. 3, figs. 

 4, 9 to 11. A. RaciborsHi Berl. in Sacc. Syk 1 ., vii. 430 



(1888) ? A. cornuvioides Racib. in Hedw.. xxviii. 123 



(1889) ? A. clavata Cel. fil. Myx. Bohm., 29 (1893). Trkhia 

 polymorpha Sow. Engl. Fung., t. 180 (1799) (nomen). 



Var. Heterotrichia Torrend Fl. Myx., 98 : capillitium a 

 dense network with many pointed free ends, threads closely 

 reticulated and spinulose all over, 5 to 8 fi diam. — Hetero- 

 trichia Gabriellae Mass. Mon., 140 (1892) : Macbr. I.e.. 198. 



PI. 173. — a. sporangia ; 6. c. threads from upper part of capillitium ; d. thread 

 from basal part of capillitium; e. capillitium of form named A. dictyonema Rost. 

 (Germany) ; /. capillitium of var. Heterotrichia (South Carolina) ; g. portion of spor- 

 angium-wall ; h. spores. 



The sporangia of this species vary much in colour ; large develop- 

 ments are of te'i met with in which the more central sporangia are brick- or 

 orange-red, while the outer are yellow or buff. The markings on the 

 capillitium also vary considerably ; the threads of a single sporangium 

 may be in some parts conspicuously thickened on one side while in 

 other parts they are not thickened, and are spinulose all over. In the 

 type of .4. dictyonema Rost., from Freiburg, the capillitium is spinose, 

 principally on one side of the thread, and marked with broken reticu- 



