FuLiGO 79 



sporangia, have conical masses of lime arising from the bases, h'ke 

 coiumellae, and in some of the larger ones, these are extended as 

 low ridges. The lime-knots are small, angular, and pale yellow. 

 The spores are about the same as in the American form. Neither 

 of these resemble P. virescens, as the Listers indicate, nor are they 

 related to P. contextum, as Macbride says, and the collection 

 reported by him from Washington must be regarded as doubtful. 

 The two forms may represent different species, but further Ameri- 

 can material is needed to show this. 



Genus 4. FULIGO Haller, Hist. Stirp. Helv. 3: 110. 1768. 



Sporangia elongate, branched, and interwoven, combined to 

 form a pulvinate aethalium, the outer layer of sporangia often 

 barren and forming a cortex charged with deposits of lime- 

 granules and without spores; columella none; capillitium with few 

 or many lime-knots. 



Type species : Mucor septicus L. 



Aethalium usually corticate, white, yellow, reddish, or 



brown; spores 7-10 n diam. ]. F. septica 



Aethalium ecorticate, the outer layer of sporangia well de- 

 veloped, white or ochraceous; spores 9-12 n diam. 2. F. intermedia 



Aethalium usually corticate, white; lime-knots often large; 



spores large, ellipsoid. 3. F. cinerea 



Aethalium ecorticate, yellow or grayish, surface smooth ex- 

 cept for the tops of the upper sporangia; spores 10-11 n 

 diam.; habitat in wet places. 4. F. muscorum 



Aethalium with a thick, white, spongy cortex; lime-granules 



large; spores 12-24 /^ diam., very dark and tuberculate. 5. F. megaspora 



1. Fuligo septica (L.) Weber; Wigg. Pr. Fl. Holsat. 112. 1780. 

 Mucor septicus L. Sp. Plant, ed. 2. 1656. 1763. 



Plasmodium yellow or white. Aethalia pulvinate, varying in 

 size from 2 mm. to more than 30 cm., various shades of yellow in 

 the typical form, also greenish, reddish, and brown to deep 

 chocolate. The sporangia constituting the aethalium are intri- 

 cately coiled and anastomosing, but often more or less separated 

 in the mass, with spaces in between; cortex thick or thin, a dense 

 crust of lime or undeveloped Plasmodium, loose or firm, or absent 

 entirely; sporangial walls within the aethalium membranous, 

 fragile, colorless, with scattered deposits of lime-granules. Capil- 

 litium scanty or abundant, consisting of a loose network of slender 

 hyaline threads, more or less expanded at the axils, with fusiform 



