174 ENDOSPORE^E. [HEMITRICHIA. 



been exposed to unusual conditions of development. 0. Bavaricum 

 Balf. & Berl. is described as distinguished from 0. nitens by the 

 more distinct spirals on the elaters, but the spirals are as distinct in 

 Libert's type of the species ; the spores of the Bavarian gather- 

 ing vary in size from 12 to 16 /*, and the reticulation also varies 

 so as to present from four to sixteen meshes on the surface of the 

 hemisphere. The type specimens of O.flavidum Peck and 0. brevi- 

 filum Peck differ from one another only in the former having more 

 papillose and longer elaters than the latter, and spores measuring 

 12 to 14 p,, while in 0. brevifilum they measure 10 to 12 p. ; they 

 scarcely differ from the specimen named 0. Bararicum, and are here 

 included under 0. nitens. The type specimens of 0. minutulum Mass., 

 from Algiers (B. 1739), and Physarum ScJiweinitzii Berk., from Beth- 

 lehem, U.S.A. (K. 1738), are typical 0. nitens. The descriptions of 

 Trichia Kickxii Rost. and T. pusilta Schroet. agree so perfectly with the 

 character of 0. nitens that they are here placed as synonyms of this 

 species. 



Hob. On dead wood. Near Birmingham (L:B.M.144); Belgium 

 (B. M. 747); Germany (Strassb. Herb.); Bavaria (B. M. 746); 

 Algiers (K. 1739); Philadelphia (L:B.M.144) ; Ohio (L:B.M.144); 

 Iowa (B. M. 1031) ; S. Carolina (B. M. 960, 961, 964). 



SPECIES NOT MET WITH IN THE QUOTED COLLECTIONS. 



2. 0. aeneum Karst., Myc. Fenn., iv., in Bidr. Kami. 

 Finl. Nat. (1879), p. 131. Sporangia densely crowded, often 

 confluent and vein-like, rarely scattered, globose, or angled by 

 mutual pressure, depressed, shining, metallic copper, greenish 

 or olivaceous ; capillitium tubes free, with scattered ring-shaped 

 thickenings, 2 to 3 /x, thick; spores warted, reddish- or pale 

 yellowish-ochre, 12 /x diam. 



Hob. On pine-wood. Mustiala, Finland. 



3. 0. furcatum Bucknall, in Mass., Mon., p. 173. Sporangia 

 scattered, globose, shining, bright chrome-yellow, as well as the 

 capillitium and spores ; elaters cylindrical, simple or branched, 

 slightly thickened at the obtuse ends, with a faint open spiral, 

 3 to 4 fji diam. ; spores globose, minutely warted, 11 to 12 p diam. 



Hob. On a rotting trunk. Abbots Leigh, Somerset, England. 



SPECIES EXCLUDED FROM THE GENUS. 



0. Broomei Mass. = Perichcena populina Fr. 



Genus 35. HEMITRICHIA Rostafinski, Versuch, p. 14 (1873). 

 Sporangia stalked or sessile ; capillitium an elastic network of 

 more or less branching threads, thickened with two to six spiral 

 bands; spores minutely warted or reticulated. HEMIARCYRIA 

 Host., Mon., p. 261 (1875). 



I have restored the original name which Rostafinski gave to this 

 genus, being in accordance with the laws of botanical nomenclature, 

 while at the same time it expresses more accurately the affinities of 

 the group. 



