CORRECTIONS OF THE PLATES. 



Plate IV., for Zonotricha read ZonotricUa. 



Plate VIII., for urn in the terminations of the specific name of figures 2, 3, 



and 4, read us. 



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



Plate X., fig. 4, for Botryococcus pulckellus read Dictyosphcerium pulchellum. 

 Plate XI., fig. 5, 6, and 7, for Cosmarium read Closterium. 

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

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

 Plate XVI., fig. 4, for Bulbotricha read BulbotriMa. 

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

 Plate XXI., fig. 7, for tetraopthalmum read tetropthalmum. 



