22 



MICROSCOPICAL OBSERVATIONS. 



VOLUSIA, ON THE ST. JOHN S RIVER, FA. 



On the roots of the " Water Lettuce," Pistia stratiotes, L.,t I collected at 

 Volusia, on the 9th of" April, 1850, the following species, viz : 



DiatomacejE. Navicula elongata, Harrison ? 



Achiianthes, undetermined. See fig. 11, PL 2. Odontella polymorplia, Kg. 



Ampliora libyca, Ehr. Fig. 12, PL 12. Synedra vitrea, Kg. 



Bacillaria paradoxa, Ehr. Abundant, and very Terpsinoe musica, Ehr. Living, and forming zigzag 



active. chains. 



Cocconeis pediculus, Ehr. — 



Cooconema cymbiforme, Eiir. Infusoria. 



Eunotia gibba, Ehr. Amoeba princeps, Ehr. 



" nodosa, Ehr. Arcella vulgaris, Ehr. 



hbrile, Ehr. Rotifer vulgaris, Schr. 



Galhonella aurichalcea, Ehr. — 



" variiuis, Ehr. Desmidie^e. 



Himantidium arcus, Ehr. Staurastrum enorme, Ralfs. 



ENTERPRISE, FA. 



Latitude between 28" and 29° N. 



April lOth to 23d, 1850. — On Lake Monroe, 200 miles from the mouth of the 

 St. John's River. This was the most southern point which I visited, and there 

 is no place which I have ever seen which afforded so many delights to the micro- 

 scopist. The sub-tropical climate produces in the numerous lakes and creeks 

 countless myriads of the most interesting Infusoria and Desmidieae, which may 

 be collected within a few hundred yards of the boarding-house. The numerous 

 sulphur springs, surrounded by beautiful palmetto groves ; the parasitic Tillan- 

 dsias of several species; the epidendri and parasitic ferns; the lake with its hun- 

 dreds of alligators, and its strange mixture of marine and fresh-water forms ; and 

 lastly, the wonderful shell banks on which Enterprise is built, are all calculated 

 to interest even the most indifferent. I would be glad if every invahd who 

 visits this place could pass as many pleasant hours there as it was my privilege 

 to enjoy. 



In Lake Monroe I collected, from among the roots of Pistia stratiotes, the fol- 

 lowing species, viz : 



Desmidie^. 

 Closterium Jenneri, Ralfs. 

 Euastrum ampullaceum, Ralfs. 

 Pediastrum boryanum, Menegh. 



Alg^. 

 Coleocheete scutata, Breb. 

 Spyrogyra quinina, Kg. 



DlATOMACE^. 



Amphiprora constricta, Ehr. PL 2, figs. 5, 6, V. 



* " pulchra, B. PL 2, figs. 16 and 18. 

 Bacillaria paradoxa, Ehr. 



Campylodiscus clypeus, Ehr. 



* " argus, B. PL 2, figs. 24, 25. 

 Cocconeis pediculus, Ehr. 



Cocconema cymbiforme, Ehr. 



f This gigantic representation of the Lemna of the northern waters grows in vast profusion in the 

 Withlacoochee and St. John's Rivers. Like the Lemna, it contains spiral vessels in its roots, and abounds 

 with Biforines, which actively discharge their raphides in water. See PL .3, fig. 1. 



