248 ENDOSPOREAE [PERICHAENA 



I. P. chrysosperma Lister. Plasmodium pale brown. 

 Sporangia scattered, sessile, rarely shortly stalked, sub- 

 globose or forming curved or ring-shaped plasmodiocarps, 

 0*4 to 1 mm. diam., chestnut, red-brown or blackish-brown, 

 dehiscing irregularly ; sporangium-wall of two layers, the 

 outer composed of brown granular matter, which either forms 

 a complete crust, or is more or less obsolete ; the inner layer 

 subcartilaginous, pale yellowish-olive, translucent. Stalk, 

 when present, stout, black, 0-1 to 0-7 mm. high. Capillitium 

 abundant, forming a loose network of sparingly branched 

 yellow threads 2to4/x diam., irregularly constricted, studded 

 with scattered spinules or curved spines, 1 to 6 p, long. Spores 

 citron-yellow in mass, minutely warted, 9 to 10 p. diam., rarely 

 7 to 8 fi.— Torrend Fl. Myx., 90 ; Petch in Ann. Perad., 

 iv. 368. Ophiotheca chrysosperma Currey in Quart. Micr. 

 Journ., ii. 240, t. ix, figs. 1-5 (1854) ; Macbr. X. Am. 

 Slime-Moulds, 182. O. Wrightii Berk. & Curt, in Journ. 

 Linn. Soc, x. 349 (1869) ; Mass. Mon. ; 132 : Macbr. I.e. 

 O. circumscissa Mass. I.e., 131. Trichia circumscissa Walk. 

 Fl. Crypt. Germ., 378 (1833) ? T. Curreyi Crouan Fl. Finist., 

 16 (1867). Arcyria glomerata Fr. Summ. Veg. Scand., 457 

 (1849) ? Comuvia circumscissa Rost. Mon., p. 290 (1875). 

 C. Wrightii Rost. Mon.. App. p. 36 (1876). Hemiarcyria 

 melanopeziza Speg. in Ann. Soc. dent. Argent., x. 257 (1881). 



PI. 184. — a. stalked and sessile sporangia ; b. various forms of capillitium from 

 sporangia on the same piece of bark, with spore and fragment of sporangium-wall. 



In Rostafinski's description of the genus Perichaena the capillitium 

 is said to be without characteristic thickenings. P. corticalis to 

 which this definition most nearly applies has the capillitium threads 

 warted and notched, rarely smooth, while in other species of the genus 

 the threads are never smooth, but a fl e marked with minute warts, 

 spinules or spines. In P. chrysosperma there may be considerable 

 difference in the amount of roughnes • of the capillitium in a single 

 group of sporangia. In a gathering made at Lyme Regis, two of the 

 sporangia examined have almost smooth threads marked only with 

 a few minute scattered spines, other sporangia have spines 2 - 5 p. long, 

 and others have the threads studded with curved spines 5 to 6 - 5 p 

 long. The type of Ophiotheca chrysosperma Currey (B.M. 308) has the 

 capillitium marked with spines 1 to 4/x long. The type of Comuvia 

 Wrightii Rost. from Cuba (B.M. 699) shows sporangia similar in all 

 respects to Currey's gathering From the original account of Trichia 

 circumscissa Wallroth it is probable that the specimen described was 

 not the present species but Perichaena depressa ; the specific name 

 given by Currey is therefore here adopted. 



Hab. On dead bark. — Lyme Regis, Dorset (B.M. 1520) ; Bohemia 

 (Herb. Dr. Celakovsky) ; Portugal (B.M. 3120) ; Ceylon (K. 1712) ; 

 Japan (B.M. slide) ; Philadelphia (B.M. 1522) ; Iowa (B.M. slide) ; 

 Ohio (B.M. 1521); Cuba (B.M. (399) : Antigua (B.M. 1689) ; Brazil 

 (B.M. 3121). 



