134 THE WORTH AMERICAN SLIME-MOULDS 



4. Diachea Fries. 

 1825. Diachea Fries, Syst. Orb. Veg., I., p. 143. 



Sporangia distinct, globose or cylindric, the peridium thin, 

 iridescent, stipitate ; the stipe and coluraella surcharged with 

 lime, white or yellowish, rigid, thick, tapering upward ; capilli- 

 tium of delicate threads free from lime, radiating from various 

 points on the columella, branching and anastomosing as in 

 Comatricha to form a more or less intricate network, the ulti- 

 mate branchlets supporting the peridial wall. 



Rostafinski placed this genus near the Didymiece on account 

 of the calcareous columella and the non-calcareous capillitium. 

 On the other hand the structure of the capillitium and the 

 iridescent simple peridium ally Diachea to Lamproderma and 

 the Stemonitea ; the only distinction being the calcareous stem. 

 It is simply an intermediate genus to be placed here more con- 

 veniently than anywhere else in what is of necessity a linear 



arrangement. 



Key to the Species of Diachea. 



A. Stipe and columella white. 



a. Sporangium cylindric . . . . I. D. leucopoda 



b. Sporangium globose . . . . 2. D. splendens 



B. Stipe yellowish or orange 3. D. thomasii 



i. DIACHEA LEUCOPODA (Bull.} Rost. 



1791. Trichia leucopodia Bulliard, Champ, de la France, PI. 502, Fig. 2. 

 1825. Diachea elegans Fries, Syst. Orb. Veg., I., p. 143. 

 1875. Diachea leucopoda (Bull.) Rost., Matt., p. 190. 



Sporangia rather closely gregarious, metallic blue or purple 

 iridescent, cylindric or ellipsoidal, obtuse, sub-umbilicate below, 

 stipitate ; stipe short, much less than one-half the total height, 

 snow white, tapering upward ; hypothallus white, venulose, 

 occurring from stipe to stipe to form an open network over 

 the substratum ; columella thick, cylindric, tapering, blunt, 

 terminating below the apex, white ; capillitium springing from 

 every part of the columella, of slender threads, brown, flexu- 

 ous, branching and anastomosing to form an intricate net; 



