272 



Mycologia 



breaks away entirely from the exoperidium, in which case it re- 

 sembles very much the sterile base of a Calvatia; spores globose, 

 faintly verrucose, brown, 3-5 fx in diameter ; capillitium wine- 

 colored to brown under microscope, threads very long, sparingly 

 and very distantly branched, 7-10 fi thick, tapering to a slender 

 point, septate in thicker portions, breaking up into segments 

 some of which are 800 to 1000 \x, long, walls smooth or often 

 appearing as if filled with minute pits, lumen very small or none. 



In rich, loose, sandy loam around base of old, rotting, post oak 

 (Quercus stellata) stumps. Type collected at Denton, Texas, 

 October 8, 1907, by W. H. Long (No. 201 1)} Other collections 

 were made by the writer as follows : At Denton, Texas, Septem- 

 ber, 1906, and October 14, 1907 (Nos. 167 1 and 2034). The dis- 

 tinguishing features of this plant are its prominent persistent 

 corky sterile base and its deciduous fragile endoperidium. It is 

 a Calvatia among the geasters. 



The genus is closely related to Geasteropsis Hollos, but differs 

 from this plant in having a sterile persistent base to which the 

 lower part of the endoperidium is firmly attached. According 

 to the description and figures given by Hollos, 2 the dehiscent 

 endoperidium of Geasteropsis encloses the subligneous stipe and 

 columella making quite a different plant from the one here de- 

 scribed. 



Arachniopsis gen. nov. 



Plants subglobose, terrestrial, peridium double, outer or exo- 

 peridium fragile, more or less deciduous ; endoperidium cartilagi- 

 nous, opening irregularly at apex ; gleba consisting of a powdery 

 mass of spores and capillitium without either columella or peridi- 

 oles. 



Arachniopsis albicans sp. nov. 



Plants subglobose to irregularly globose, white, 5-20 mm. 

 across, usually with a radicating base like a phalloid ; exoperidium 

 mealy to powdery, white, gradually weathering off ; endoperidium 

 cartilaginous, often very thin at apex, splitting into several ir- 

 regular tooth-like segments at top, which are more or less in- 

 curved onto the gleba; gleba powdery, drab en masse consisting 

 of spores and capillitium; spores subhyaline, with a greenish 



1 Unless otherwise stated all of the herbarium numbers cited in this article 

 refer to the herbarium numbers of the writer. 



2 Hollos, L. Novenyt. Kozlem. 2: 72-75. 1903. 



