426 



White : Tylostomaceae of North America 



find among them several additional species. The indications are 

 that we are only at the beginning of our knowledge of their distri- 

 bution. 



The following table shows the distribution of the hitherto 

 known species of Tylostoina : 



The species of Tylostoma are found principally in sandy regions, 

 in dry barren fields, rarely in woods or shaded places. As yet 

 very little is known of their habits, growth and development as no 

 little difficulty attends the study of these strange and interesting 

 plants in their early subterranean stages. It is hoped that stu- 



