64 THE MYCETOZOA 



convoluted sporangia forming a tissue of interarching bands. Reticularia, 

 Bulliard. Walls of convoluted sporangia forming tubes and folds with 

 numerous anastomosing threads. 



ORDER 5. Lycogalaceae. 



Sporangia forming an aethalium ; pseudo-capillitium consisting of 

 branched colourless tubes, the remains of the walls of the fused sporangia. 

 Genus Lycogala, Micheli. 



SUB-COHORT B. CALONEMINEAE. 

 Capillitium a system of uniform threads. 



ORDER 1. TricMaceae. 



Capillitium threads with spiral or annular thickenings. Free or 

 united into an elastic network. Trichia, Haller (Figs. 11, 12, and 15, a-c). 

 Capillitium abundant, threads free, with spiral thickenings. Oligonema, 

 Rost. Capillitium scanty, threads free, with imperfect spiral thickenings. 

 Hemitrichia, Rost. (Fig. 15, d). Capillitium threads combined into a net- 

 work, with spiral thickenings. Cornuvia, Rost. Sporangia in the form 

 of plasmodiocarps ; Capillitium threads combined into a network, with 

 annular thickenings. 



ORDER 2. Arcyriaceae. 



Capillitium combined into an elastic network with thickenings in the 

 form of cogs, half-rings, spines, or warts. Genera Arcyria, Hill (Fig. 

 15, e-/). Sporangia stalked ; sporangium wall evanescent above, persistent 

 and membranous in the lower third. Lachnobolus, Fries. Sporangia 

 sessile, clustered ; sporangium wall single, persistent, not thickened with 

 granules. Perichaena, Fries. Sporangia sessile or in the form of plas- 

 modiocarps ; sporangium wall double, at least at the base, the outer layer 

 thickened with angular granules. 



ORDER 3. Margaritaceae. 



Sporangia normally sessile ; sporangium wall single, smooth, trans- 

 lucent ; capillitium abundant, not consisting of separate threads, nor 

 combined into a net. Genera Margarita, Lister. Capillitium profuse, 

 long, coiled, and hair-like. Dianema, Rex. Capillitium of nearly 

 straight threads, without spiral thickenings, attached at both ends to the 

 sporangium walls. Prototrichia, Rost. Capillitium of fasciculate threads, 

 attached above or below to the sporangium wall, and spirally thickened. 



DIVISION II. EXOSPOREAE. 

 Spores developed on the surface of sporophores. 



ORDER 1. Ceratiomyxaceae. 



Sporophores fragile and evanescent, branched ; spores white, borne 

 singly on filiform stalks arising from the areolated sporophore. Genus 

 Ceratiomyxa, Schroeter (Fig. 18). 



