LAMPRODERMA 197 



As the changes approach maturity, the sporangia become jet-black, 

 and only at last when the spores are ready for dispersal does the 

 peridium assume its rich metallic purple tints. Colonies a meter in 

 length, two or three decimeters in width, are sometimes seen ! 



New England, New York, Pennsylvania, Ohio, Indiana, Illinois, 

 Iowa, South Dakota; Toronto. Common. 



6. Lamproderma arcyrionema Rost. 



Plate V., Figs. \, \ a. 

 1875. Lamproderma arcyrionema Rost., Mon., p. 208. 



Sporangia gregarious, scattered, globose, silvery gray or bronze, 

 iridescent, erect, stipitate; stipe black, long, two-thirds to three- 

 fourths the total height, slender, rigid; columella slender, cylindric, 

 attaining about one-third the height of the sporangium when it 

 breaks into the primary branches of the capillitium; capillitium ex- 

 ceedingly intricate, made up of slender, flexuous brown threads which 

 frequently branch and anastomose to form an elegant round-meshed 

 network resembling that of Arcyria, free ultimate branchlets not 

 numerous; spores in mass jet-black, by transmitted light violaceous, 

 smooth, or only faintly warted, 6-8 yu.. 



In outward appearance this species resembles L. physaroides, but is 

 easily recognizable by its very peculiar capillitium. This, in its pri- 

 mary branching, resembles a comatricha. In typical forms, the colu- 

 mella branches at the apex only, generally into two strong divisions 

 which then break up irregularly and anastomose in every direction. 

 This seems to have been the form present to Rostafinski when he 

 wrote "columella truncate." In Central American and some North 

 American specimens, the branching is very different ; the twigs leave 

 the columella at various points almost down to the annulus, and the 

 entire effect is dendroid. The columella is lost almost at once. A 

 small form of this species was formerly distributed in the United 

 States as Comatricha friesiana DeBy. This circumstance led the 

 present author to describe Central American forms as C. shimekiana. 

 Judging from a remark by Massee {Mon., p. 97), a similar confusion 

 seems to have prevailed in Europe. As a matter of fact, the resem- 



