ORDER AURICULARIALES 443 



celled epibasidium. The somewhat allantoid basidiospores are produced 

 on distinct sterigmata. In structure of the sporiferous portion of the fruit 

 body the fungi of this genus show considerable similarity to Septohasid- 

 ium, to which Couch suggests that they may be transitional forms. 



Helicobasidium is parasitic on the roots or crowns of trees and shrubs 

 or perennial herbaceous plants, and also may grow as a saprophyte. H. 

 purpureum (Tul.) Pat. has been studied by Buddin and Wakefield (1927). 

 On the surface of the substratum it forms a nongelatinized, effused, felted 

 layer. The basidial primordia are often more or less coiled. They become 

 hypobasidia from whose apex grows out the terminal hooked epibasidium 

 which produces sometimes rather long sterigmata. In H. candidum 

 Martin (1940) the hypobasidium is small, forming practically only a short 

 slender stalk for the stout curved basidium. Clamp connections are pres- 

 ent. Syzygospora, with a single species S. alba was described by Martin 

 (1937a). It forms a white gelatinous spore fruit up to 10 cm. long and 2.5 

 cm. thick, the surface covered by the hymenium. The basidia occur in 

 sympodial fascicles. They have but a single septum with a basal cell more 

 or less elongated and clavate and the terminal cell spherical. A single 

 spherical basidiospore is produced from each cell, near the base of the 

 apical cell of the basidium and near the top of the basal cell. Thus the 

 spores come into contact and unite to form an ellipsoid spore. Martin 

 compares this with the union of two sporidia while still attached to the 

 promycelium of some smuts. The hyphae are abundantly provided with 

 clamp connections. (Fig. 144 C.) 



Platygloea is waxy or gelatinous, resupinate, and effused, mostly grow- 

 ing on wood. Usually there is no distinction into hypobasidium and epi- 

 basidium. Helicogloea (Saccohlastia) has many of the same characteristics 

 but is more gelatinous. It also grows on dead wood. A distinct, usually 

 lateral and hanging pyriform hypobasidium is conspicuous. The basidial 

 primordia are usually terminal but may be intercalary. (Fig. 144 D, E.) 



Auricularia forms the largest and most conspicuous spore fruits of this 

 family. They are borne on branches or trunks of trees and are especially 

 abundant in the Tropics. The common species of the Temperate Zones is 

 A. auricularis (S. F. Gray) Martin {A. auricula- judae or Hirneola auricula- 

 judae of most authors). The spore fruits are gelatinous and more or less 

 ear-shaped when moist, and of a translucent brown color, but dry down to 

 small dark horny masses. The basidia form a hymenium on the lower 

 surface, standing parallel in a sort of palisade immersed in the gelatinous 

 matrix. The elongated basidial primordia become divided by three trans- 

 verse septa and from each of the cells grows a tube-like extension to the 

 surface of the matrix where a sterigma is formed bearing a single basidio- 

 spore. The tropical genus Tjibodasia is waxy, and more or less pezizoid in 



