of Microscopical Organisms. 



:i47 



To the above, most of which have been observed by 

 both my father and myself. I can now add several other 

 forms not observed by him. They are as follows : 



Cocconema. 



Triceratium mcgastomum, Ehr. 



Ceratoneis? spiralis, K. 



Eupodiscus crassus? 



Epithemia. 



Hyalodiscus Californicus, B. 



Cymbella. 



Spongiolites Agaricus, Ehr. 



Amphora obtecta? B.* 



Navicula firma. 



Rotalia. 



Globigerina, &c. 



and several undetermined minute Cocconeidce. Tims we 

 have at least eighty -three distinct species occurring in the 

 Para and Amazon, of which thirty would seem to be new. 

 There are one or two other forms occurring here, which I 

 believe to be undescribed, and which I may present at 

 some future time. I pass now to the second portion of 

 the plate, which includes forms also obtained during the 

 cruise of the Dolphin, with the exception of Figs. F 

 and G. 



