168 PHYCOMYCETEAE 



Note : An additional genus of the Choanephoraceae was published too 

 late to appear in the text of this chapter. Cokeromyces Shanor (type 

 species C. recurvatus Poitras) produces numerous sporangioles on elon- 

 gated recurved stalks arising from the terminal capitate swelling of the 

 sporangiophore. Twelve to twenty spores are produced in each sporangi- 

 ole, lacking the striae and appendages found in other genera of the family. 

 No true sporangia are produced. Zygospores arise in the manner of Mucor 

 and Cunninghamella. 



Shanor, Leland, Adrian W. Poitras, and R. K. Benjamin: A new 

 genus of the Choanephoraceae, Mycologia, 42(2) :27 1-278. Figs. 1-12. 

 1950. 



Family Piptocephalidaceae. The species of this family are largely 

 parasitic on other Mucorales although some are saprophytic. The spo- 

 rangia are narrow and more or less clavate or cylindrical, with the spores 

 usually in one row, often appearing when mature like chains of conidia. 

 The number of spores formed in the sporangium varies from two (rarely 

 one) to 30. Usually the sporangium breaks into monosporous segments, 

 the spore being enclosed in the sporangial wall. In a few cases the whole 

 sporangium may break off and the spores escape individually from the 

 opening. In Syncephalis the sporangiophore is upright and unbranched, 

 tapering from the more thickened basal portion up to the enlarged, 

 usually spherical head which may be upright or nodding. The radiating 

 sporangia may arise directly from the surface of this head or singly or 

 several together upon short " sterigmata. " These sporangia may be de- 

 hiscent at maturity letting the contained two to several spores escape. 

 In Syncephalastrum the sporangiophore is mostly branched as in the 

 racemose type of Mucor. On the spherical heads terminating the branches 

 the narrow sporangia arise radially without the intervention of sterig- 

 mata. These break apart into monosporous segments so that they were 

 long considered to be true conidia and compared to the chains of conidia 

 formed on the swollen heads of the conidiophores of Aspergillus. In Pipto- 

 cephalis the sporangiophores are dichotomously branched, bearing at the 

 tips of the branches slightly enlarged segments ("sterigmata") of various 

 shapes from which arise several sporangia which break up into one-spored 

 pieces. In Dispira the terminal heads of the much branched sporangio- 

 phore bear two-celled "sterigmata" from each of which arise short spo- 

 rangia of from two to several spores. The genus Spinalia (Vuillemin, 

 1904) probably belongs in this family. It has a coenocytic mycelium and 

 produces heads covered by "conidia." On the spherical heads the so- 

 called "conidia" occur in chains of two. According to Vuillemin (1922) 

 the zygospores are formed by the Mucor type of sexual reproduction in 

 Syncephalastrum. In Piptocephalis and Syncephalis sexual reproduction 



