CORRECTIONS OF THE PLATES. 



Plate IV., for Zonolricha read Zonotrichia. 



Plate VIII., for um in the terminations of the specifio name of figures 2, 3, 



and 4, read us. 

 Plate IX., fig. 3, for argillacea read argillaceus. 



Plate X., fig. 4, for Botryococcus pulchcUus read Dicti/oxphwrium pulchellum. 

 Plate XI., fig. 5, 6, and 7, for Cgsmarium read Cluster turn. 

 Plate XII., fig. 1 and 20, for Cosmarium read Closterium. 

 Plate XV., fig. 8, for iiisignis read insigne. 

 Plate XVI., fig. 4, for Bulhotricha read Bulbotrichia. 

 Plate XVIII., fig. 1, for Pringsheimii read Priniisluimia. 

 Plate XXI., fig. 7, for tctraopthalmum read tetrojithal mum. 



