978 NEW YORK STATE MUSEUM 



tough and flexible inner membrane or peridium. With advanc- 

 ing age this assumes a dull grayish blue or leaden hue and 

 opens by a small aperture at the top for the escape of the 

 spores. Any sudden pressure applied to it at this time will 

 cause the ejection of a mass of its spores in little smokelike 

 puffs as in other puffballs. Occasionally old specimens are 

 found in which the inner peridium is almost black. The small 

 size, peculiar color and distinctly double coat of the immature 

 plant are characters which make this bovista easily recog- 

 nizable. Its flavor is much more agreeable than that of many 

 of the small species of the genus Lycoperdon. 



EXPLANATION OF PLATES 



l PLATE K 



Clitocybe regularis Pk. 



Regular Clitocybe 



FIG. 



1 Immature plant 



2 Mature plant with convex cap 



3 Mature plant with nearly plane cap 



4 Vertical section of an immature plant 



5 Vertical section of the upper part of a mature plant 



6 Transverse section of a stem of a mature plant 



7 Four spores x 400 



Clitocybe subconcava Pk. 

 Subconcave Clitocybe 



8 Plant with the cap moist 

 9, 10 Two plants with caps dry 



11 Vertical section of the upper part of a plant 



12 Transverse section of a stem 



13 Four spores x 400 



Hydnum umbilicatum Pk. 

 Umbilicate Hydnum 



14 Immature plant showing the upper surface of the cap 

 15, 16 Two mature plants showing both surfaces of the cap 



17 Vertical section of the upper part of a plant 



18 Four spores x 400 



