16 



MICROSCOPICAL OBSERVATIONS. 



PILES' " NEW PLACE," FA. 



At " Piles','' about forty miles west of Pilatka, on the road to Tampa, I exa- 

 mined the rock recently excavated in forming a well. It proved to be the 

 White Orbitulite limestone, containing large masses of flint. Both the limestone 

 and flint abound in microscopical Polythalamia, which may be detected in the flint 

 by mounting thin fragments in Canada balsam. Rock of similar character was 

 seen at numerous places between Pilatka and Tampa, and it even forms exten- 

 sive ridges, of the height of three or four hundred feet, giving an appearance 

 to the interior of Florida very different from the flat monotonous aspect which it 

 is generally supposed to present. 



OCALA, FA. 



Feb. 2Gth, 1850. In a " Lime-sink" near Ocala, on the road to Tampa, I found 

 the following forms among the roots of Lemna minor, which covered the surface 

 of the water, viz : 



Docidium nodulosum, Breb. 

 Cosmarium Thwaitesii, Ralfs. 



" margaritaceum, Menegh. 



Arcella vulgaris, Ehr. 

 Euglena pleuronectes, Ehr. 

 Rotifer vulgaris, Schr. 



Salpina mucronata, Ehr. 



*Aporca ambigua, B. 

 Coleochsete scutata, Breb. 

 Tyndaridea cruciata, Harv. 

 Spirogyra quinina, Kg. 



DADE S BATTLE GROUND, FA. 



At the pond near Dade's Battle Ground, I found the following forms, viz 



DESMIDIE.-E. 

 Arthrodesmus convergens, Ehr. 



" incus, Breb. 

 *Cosmariuni depressum, B. 

 connatuxu, Breb. 

 margaritiferum, Menegh. 

 " ornatum, Ralfs. 

 Docidium minutum, Ralfs. 

 Euastrum binale, Ralfs. 



" elegans, Breb. 

 Micrasterias crenata, Breb. 

 " incisa, Kg. 



" pirmatifida, Kg. 



radiosa, Ag. 



DESMIDIE.E. 



*Micrasterias ringens, B. 

 Pediastruni Boryanum, Menegh. 



" heptactis, Menegh. 

 *Sph;erozosma serratum, B. 

 Xanthidium cristatum, Breb. 



INFUSOKIA. 

 Arcella dentata, Ehr. 

 *Difflugia spiralis, B. 

 Gonium glaucum, Ehr. 

 Rotifer vulgaris, Schr. 

 Salpina mucronata, Ehr. 



