PLATE XIX. 



Fig. i. Onagra lamarckiana and Onagra nanella in bloom. 



Photographed at 6 a. m., August g" 1904. 



Fig. 2. Onagra lamarckiana X Onagra biennis. 



No. 2.32 at left and right in foreground ; No. 2.24 in center. 



