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 : 



DIATOMACE.E. N<u icula elongatii, Harrison ? 



Achnanthes, undetermined. See fig. 11, PL 2. Odontella polyraorpha, Kg. 



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



Bacillaria paradoxa, Ehr. Abundant, and very Terpsinoii musiea, Ehr. Li vino-, mid forming zigzag 



active. rliains. 

 Cocconeis pediculus, Ehr. 



Cocconema cymbiforme, Ehr. INFUSORIA. 



Eunotia gibba, Ehr. Amoeba princeps, Ehr. 



" nodosa. Ehr. Arcella vuluraris, Ehr. 



O 



" librile, Ehr. Rotifer vulgaris, Schr. 

 Gallionella aurichalcea, Ehr. 



varians, Ehr. DESMIDIE^E. 



Himantidium arcns, Elir. Staurastrum enorme, Ralfs. 



ENTERPRISE, FA. 



Latitude between 28 and 29" N. 



April 10th 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 Desmidiese, 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 invalid 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/E. DIATOMACE.E. 



Closterium Jenneri, Ralfs. Amphiprora constricta, Ehr. PI. 2, figs. 5, 6, 7. 

 Euastrum ampullaceum, Ralfs. pulchra, B. PL 2, figs. 16 and 18. 



Pediastrum boryanum, Menegh. Bacillaria paradoxa, Ehr. 



Campylodiscus clypeus, Ehr. 



ALG^E. argus, B. PL 2, figs. 24, 25. 



Coleochfete scutata, Breb. Cocconeis pediculus, Ehr. 



Spyrogyra quinina, Kg. 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 I'lilWnies. which actively discharge their raphides in water. See PI :?. fig. 1. 



