208 THE NORTH AMERICAN SLIME-MOULDS 



Sporangia closely crowded, tubular, cylindrfc or prismatic by mu- 

 tual pressure, connate, the apices rounded, convex, covered by a con- 

 tinuous membrane, umber-brown ; the peridia firm, persistent, 

 minutely granular, iridescent; hypothallus well developed, thin, 

 brown, explanate; pseudo-columellas erect, rigid, traversing many of 

 the sporangia, and in some instances bound back to the peridial walls 

 by slender, membranous bands or threads, a pseudo-capillitium ; 

 spore-mass dark brown or umber, spores by transmitted light pale, 

 globose, reticulate, 7.5-9 /x. 



This is Siphoptychium casparyi Rost. In Bot. Gaz., XV., p. 319, 

 Dr. Rex shows that the relationships of the species are with Tubifera; 

 that the so-called columella is probably an abortive sporangium, the 

 so-called capillitial threads having no homology with the capillitial 

 threads of the true columelliferous forms. It is a good species of 

 Tubifera, nothing more. The tubules are shorter than in either of 

 the preceding species; the spores are darker, larger, and more thor- 

 oughly reticulate. 



The Plasmodium is given by Dr. Rex, /. c, as \vhite, then "dull 

 gray tinged with sienna color," then various tones of sienna-brown, to 

 the dark umber of the mature jethalium. 



New York, Adirondack Mountains ; Allamakee Co., Iowa. 



3. Alwisia Berk. &' Br. 

 Plate XIX., Figs. 5 and 5 a. 

 1873. Alivisia Berk. & Br., Jour. Linn. Soc, Vol. XIV., p. 86. 

 Sporangia ellipsoidal, clustered, stipitate; dehiscence by the falling 

 away of the upper part of the peridium disclosing a persisting pencil 

 of capillitial threads. A single species : — 



1. Alwisia bombarda Berk. &" Br.. 

 1873. Alivisia bombarda Berk. & Br., Jour. Linn Soc, XIV., p. 86. 



Sporangia gathered in clusters of four to eight, surmounting coa- 

 lescent, or sometimes divergent stalks, rusty-brown, or pallid, the 

 peridium evanescent above; the coalescing stalks forming, especially 

 below, a clustered column, 2 mm. in height, equalling the sporangia, 

 dull reddish-brown in color; capillitium of rigid, tubular, generally 



