324 NOTES ON BRITISH MYCETOZOA. 



P. compressuni, and in the robust varieties of P. nutans; in P. 

 nucleatum Eex and P. compactum List, it is almost always present 

 as a central ball ; at the same time we learn from the late Dr. Rex 

 that in P. nucleatum the lime-knots are not always confluent, but 

 are sometimes distributed throun;hout the capillitium. I therefore 

 place the species in the genus Plu/sanim, and in the Guide to the 

 British Mycetozoa in the British Museum it appears under the 

 name of Physarum Crateriachea. 



Chondrioderma simplex Schroet. ? I am indebted to Messrs. 

 J. & E. Saunders, of Luton, for the history and specimens of a 

 mycetozoon, which I have provisionally named as above from the 

 short description given by Schroeter, under correction by those 

 who may have seen the type. While on a -tour in N. Wales, 

 Messrs. Saunders noticed in a wild bog a growth of yellow-brown 

 Plasmodium on Hphaguum : they detached it, with the surrounding 

 moss, and carefully protected it until it matured and produced 

 about fifty sporangia. A mounted preparation and a few sporangia 

 are in the British Museum collection. Although classed as a 

 Chondrioderma, it differs from the other known species of the genus 

 in the single, hyaline, membranous sporangium-wall, which, with 

 the hypothallus, is beset with bright brown granules of a globular 

 form, measuring 1-1'5 /x diam. These granules are crowded in the 

 columella, and are often strung like beads along the delicate threads 

 of the capillitium. It is an interesting form, taking an intermediate 

 position between the genus Chondrioderma and the genus Tricham- 

 phora, and is worthy of being recorded, although a single gathering. 

 Schroeter' s description is as under : — 



Chondrioderma simplex Schroet. Krypt. Fl. Schles. iii. p. 123. 

 Sporangia globose, somewhat depressed, solitary ; sporangium-wall 

 simple, brittle, bright chocolate-brown ; columella wanting ; capil- 

 litium radiating, repeatedly branched, violet; spores violet, smooth, 

 7-9 /A diam. 



Hab. On old stumps. 



The following are the characters of the Welsh gathering : — 



Sporangia sessile, subhemispherical, about 0*5 mm. diam., 

 crowded, pinkish brown or dull brick-red, seated on an abundant 

 red hypothallus ; sporangium-wall (when magnified 600 times) 

 single, membranous, hyaline, beset with somewhat scattered bright 

 brown granules 1*2 // diam. Columella thin ; a rugose thickening 

 of the base of the sporangium, densely charged with brown granules. 

 Capillitium profuse, consisting of delicate, colourless, seldom violet, 

 ~ branching threads, sometimes beaded with brown granules. Spores 

 violet-brown, minutely and closely warted (when magnified 1200 

 times), 10-12 fx diam. 



Hab. On Sphoffmim. 



In comparing these two descriptions, it will be observed that 

 the Welsh specimen differs in the crowded sporangia, in the colour 

 of the capillitium, and in the size of the spores ; while the structure 

 of the sporangium-wall, which is the most important character, is 

 left in uncertainty in Schroeter's account. It may be that the new 

 gathering is a species not hitherto recorded, but, considering the 



