Tubulina. Protodermium. 43 



(Type in Herb. Berk. n. 10848.) 



On dead bark. Texas. 



The type specimen is so thoroughly crushed that it is im- 

 possible to say whether the plant is a Licea or a Tubulina, but 

 in all probability the latter, as there appear to be indications 

 of the bases of crowded sporangia. 



Tubulina caespitosa, Mass. 



Peridia aggregated in tufts or clusters, crowded, sessile, 

 smooth, brown or blackish-brown ; spores dingy ochre, smooth, 

 globose, .00025 in. in diameter (=5.5 /x). 



Physarum caespitosum, Peck, 26th Report, State Mus. N. York, 

 p. 75. 



Rotten wood. Greenbush ; U. States. 



PROTODERMIUM, Rost. 



Sporangia simple, solitary, regular in form ; mass of spores 

 blackish violet ; capillitium entirely absent. 



Protoderma, Rost., Mon., p. 90; Schroeter, p. 103; Cooke, 

 Myx. Brit, p. 10. 



Protodermium, Sacc., Syll., Vol. vii., pt. I., p. 325. 



Rostafinski's name Protoderma was altered by Berlese in 

 Saccardo's Sylloge to Protodermium, as the former had been 

 already used for a genus of algae. 



The present genus is identical with Tubulina except in the 

 colour of the spores, a character which I look upon with doubt. 

 Colour as presented by spores is undoubtedly of some signifi- 

 cance, but being altogether in ignorance as to its relative 

 physiological value, I cannot accept colour in Rostafinski's 

 sense as being of such supreme importance as to constitute the 

 basis for the primary divisions of the Myxogastres, even if the 

 divisions indicated had really existed in nature, which however 

 is far from being the case. 



Distrib. Europe; United States: species 1. 



Protodermium pusillum, Rost. 



Sporangia gregarious, distinct, hemispherico-subdepressed, 

 about 1 mm. broad, chestnut-brown, shining ; mass of spores 



