168 THE NORTH AMERICAN- SLIME-MOULDS 



10. CRIBRARIA MICROCARPA (Schrad.*) Persoon. 



PLATE XVII., Fig. 4. 



1797. Dictydium microcarpon Schrad., Nov. Gen. PL, p. 13. 

 1801. Cribraria microcarpa (Schrad.) Pers., Syri., p. 190. 



Sporangia loosely gregarious, very small, .2-. 3 mm. in diameter, 

 yellow ochraceous, stipitate, nodding ; stipe comparatively stout, 

 dark brown or blackish, tapering upward, often twisted at the 

 apex as in D. cancellatum ; calyculus none, represented by 

 simple ribs which give off at intervals free or floating branchlets 

 before blending into the common net ; net well developed, the 

 meshes large, the nodes small, irregular, though often rounded 

 and prominent, black, connected by delicate transparent threads, 

 with free ends few or none ; spore-mass yellow, fading to 

 ochraceous ; spores pale, smooth, globose, 6-7 p. 



This species resembles at first sight the preceding, and has 

 been often confused with it. As a matter of fact, the distinctions 

 are generally very sharp. In the first place, the sporangia, when 

 carefully measured, are seen to be not more than half as great 

 in diameter ; the meshes of the net, on the other hand, are much 

 wider, the whole structure less compact. The nodules are like 

 those of tenella, but are much fewer. The stipe is shorter, and 

 proportionately stouter. The calyculus is almost entirely want- 

 ing, and the costse are few and simple. The color suggests C. 

 aurantiaca. The habitat and distribution as C. tenella. 



Pennsylvania, Missouri, Iowa. 



n. CRIBRARIA VIOLACEA Rex. 



PLATE XVII., Fig. 8. 

 1891. Cribraria violacea Rex, Proc. Phil. Acad., p. 393. 



Sporangia scattered or gregarious, very small, .2 mm. in 

 diameter, violet tinted, erect, stipitate ; stipe short, about one- 

 half the total height, concolorous, slender, tapering upward; 

 calyculus crateriform, persistent, costate, or marked with minute 

 plasmodic granules ; the net rudimentary or poorly developed, 

 the meshes large, irregular, the nodules also large, triangular, 

 violaceous ; spores pale violet in mass, by transmitted light 

 reddish, 7-8 /*, minutely warted. 



