866 



ORDER VIII. MYXOBACTERALES 



Polyangiden. Geb. Borntraeger, Leipzig, 

 1924, 71.) 



thax'te.ri. M.L. gen. noun thaxieri of 

 Thaxter; named for Dr. Roland Thaxter. 



Swarm stage (pseudoplasmodium) : Vege- 

 tative stages not observed. Either no germi- 

 nation or prompt cessation of growth on 

 dung extract. May be transferred on dung. 



Fruiting body: Usually 0.25 to 0.5 mm, 

 occasionally 0.75 mm in diameter. Irregu- 

 larly rounded, superficially sulfur-yellow. 

 Upon pressure numerous reddish convo- 

 luted tubules are observed embedded in a 

 yellow slime. The average diameter of the 

 tubules is about 50 microns. No membrane 

 surrounds the tubes. They contain the 



shortened rods. Enveloping slime is vari- 

 able. In well developed specimens the slime 

 forms a stalk, giving the whole the appear- 

 ance of a morel. In small specimens the rods 

 are embedded in the slime. The fruiting 

 bodies stand loosely separated on surface of 

 dung, never in large groups. Shortened rods 

 (spores) 0.5 micron by 3 microns, very 

 slender. 



Habitat: According to Jahn, found only 

 rarely on rabbit dung; races with well de- 

 veloped stalks are even less common. 



Illustrations: Jahn {ibid., PI. 1, Figs. 1-2) 

 and Krzemieniewski (Acta Soc. Bot. Pol- 

 oniae, 4, 1926, PI. II, Fig. 27). 



Genus II. Stelangium Ja/»n, 1915. 

 (Kryptogamenfiora der Mark Brandenburg, V, Pilze I, Lief 2, 1915, 205.) 



Ste.lan'gi.um or Ste.lan.gi'um. Gr. noun stele pillar or column; Or. noun angiutn vessel, 

 container; M.L. neut.n. Stelangixim columnar vessel. 



Fruiting bodies are columnar or finger-like, sometimes forked, without a definite stalk, 

 standing upright on the substrate. 



The type species is Stelangium muscorum (Thaxter) Jahn. 



1. Stelangium muscorum (Thaxter, 

 1904) Jahn, 1915. (Chondromyces muscorum 

 Tha.xter, Bot. Gaz., 37, 1904, 411; Jahn, 

 Kryptogamenfiora d. Mark Brandenburg, 

 V, Pilze I, Lief 2, 1915, 205.) 



mus.co'rum. L. noun muscus moss; L. 

 gen. pi. noun muscorum of mosses. 



Swarm stage (pseudoplasmodium) : Not 

 described. 



Fruiting body: Bright yellow-orange, 90 



to 300 microns long, 10 to 50 microns wide, 

 without differentiated stalk, simple or 

 rarely furcate, upright, elongate, compact 

 or slender, narrowed at tip. Rods (spores) 

 1 to 1.3 by 4 to 6 microns. 



Source: Found on liverworts on living 

 beech trunks in Indiana. 



Illustrations: Thaxter (op. cit., 1904, PI. 

 27, Figs. 16-18). 



FAMILY III. SORANGIACEAE JAHN, 1924. 

 (Beitrage zur bot. Protistologie. I, Die Polyangiden. Geb. Borntraeger, Leipzig, 1924, 73.) 



So.ran.gi.a'ce.ae. M.L. neut.n. Sorangium type genus of the family; -aceae ending to 

 denote a family; M.L. fem.pl.n. Sorangiaceae the Sorangium family. 



The shortened rods of the fruiting body lie in angular, usually relatively small cysts of 

 definite polygonal shape. Often many of these cysts are surrounded by a common membrane. 

 The primary cyst may be differentiated from the angular or secondary cysts. No stalked 

 forms are known. 



Genus I. Sorangium Jahn, 1924. 



(Beitrage zur bot. Protisitologie. I, Die Polyangiden. Geb. Borntraeger, Leipzig, 1924, 

 73.) 



