MUCORALES 251 



line, not having the tongs-Hke aspect seen in certain other genera; 

 terminal or intercalary, smooth, hyaline chlamydospores found 

 in some species. 



The genus is the largest in the Mucorales, over one hundred and 

 fifty species being described by Saccardo (Sylloge Fungorum) 

 for the world, and over fifty by Lendner (1908 b) for Switzerland. 

 The genus is a difficult one for the taxonomist. Notes of interest 

 on American species are given by Povah (1917). 



The genera Parasitella Bainier (1903: 153), Chlamydomucor 

 Brefeld (1889: 223; also see Calyptromyces Karst. in Sumstine 

 1910: 145), and Glomerula Bainier (1903: 154) are here embraced 

 in Mucor (see Lendner 1908 6: 69, 71, 77). 



Pilobolaceae 



! Sporangium discoid to lenticular, multispored, in most species 

 provided with a prominent sub-sporangial vesicle and at maturity 

 shot way; lower portion of sporangial wall thin and light-colored; 

 upper part heavily cutinized and black; sporangiola and conidia 

 lacking; zygospore not enclosed in a definite hyphal envelope, 

 formed at the point of union of conjugating branches which 

 have the aspect of closed tongs. 



Key to Genera of Pilobolaceae 



I. Sporangiophore provided with a large subsporangial vesicle; sporangium, 

 accompanied by columella, forcibly discharged from the sporangio- 

 phore at maturity. 



1. Pilobolus, p. 251 

 II. Sporangiophore lacking a subsporangial vesicle; sporangium not shot 

 away. 



2. Pilaira, p. 253 



1. Pilobolus Tode (Schrift. Naturf. Freimde Berlin, 5: 46, 1784). 



syn. Hydrogera Web. & Wigg. {Prim. Fl. Holstat., p. 110, 



1780); see Sumstine (1910: 136). 



Sporangiophore erect, unbranched, apically enlarged to form 



a prominent, clavate, subsporangial vesicle (Fig. 88), frequently 



also swollen at its point of origin from the mycelium, usually 



separated from the mycelium by a septum and anchored to the 



substratum by rhizoids; sporangium solitary, apical, discoid to 



lenticular, many-spored; provided with a central columella of 



much smaller diameter than the subsporangial swelling, the upper 



half of the membrane thickened and black, the lower half thin 



