270 THE LOWER FUNGI— PHYCOMYCETES 



Thaxter regards the genus as closely related to Mortierella. 

 Torrey (1921) regards the 1-spored sporangiola of Haplosporan- 

 gium as equivalent to the conidia ("stylospores") of Mortierella. 

 He then arranges a phylogenetic line in which H. bisporale ("with 

 sporangiola and stylospores") lies between H. decipiens ("with 

 only stylospores") on the one hand, and Mortierella ("with spo- 

 rangia and stylospores") on the other. 



Piptocephalaceae 



Sporangium narrowly cylindrical or rod-like, relatively few- 

 spored; sporangiospores standing in a single row, at maturity 

 having the aspect of a chain of conidia due to the dissolution of 

 the sporangial wall; zygospore usually formed in a bud put out 

 by the fusion cell resulting from the copulation of the game- 

 tangia, not enveloped in a layer of hyphae. 



Key to Genera of Piptocephalaceae 



I. Fertile sporangiferous hypha branched. 



A. Branching dichotomous or pseudodichotomous in tj'pe. 



1. Some of the branches prolonged into sterile prongs; sporan- 



giferous heads not deciduous. 



1. Dispira, p. 270 



2. All the branches terminating in sporangiferous heads; the 



latter deciduous. 



2. Piptocephalis, p. 272 



B. Branching cymose to indefinite, not dichotomous, sporangiferous 



heads not deciduous. 



3. Syncephalastrum, p. 273 

 II. Fertile sporangiferous hypha not branched below the terminal enlarge- 

 ment; provided with spur-like rhizoids at the point of attachment 

 with the substratum. 



4. Syncephalis, p. 273 



I. Dispira van Tieghem (1875: 160,^1^. 173-177). 



Mycelium parasitic on other Mucorales; sporangiophores erect, 

 repeatedly branched in a dichotomous or pseudodichotomous 

 fashion; each successive branch delimited by a septum at its base; 

 some of the terminal branches tapering into curved, sterile, 

 sharp-pointed tips; the others swollen to form spherical heads 

 over which numerous sterigmata arise bearing cylindrical spo- 

 rangia; each sterigma consisting of a single cell with a transverse 

 median constriction or of two superimposed cells, the terminal 

 one of which buds from the lower; sporangium containing a 



