MICROSCOPICAL OBSERVATIONS. 23 



ENTERPRISE, FA. continued. 



DlATOMACK.K. 1 KFUSORI A. 



Eunotia librile, Ehr. Arcella vulgaris, Khr. 



Gallionella aurichaieea. Elir. Brachionus polyacantlius, Ehr. 



Himantidium arcus, Ehr. Cnleps hirtus, Ehr. 



Navicula elongata, Har. ? Cothurnia imberbis, Ehr. 



Odontella polymorpha, Kg. Dinocharis tetractis, Ehr. 



Stauroneis maculata, B. Floscularia ornata, Ehr. 



Surirella ovalis, Breb. Opercularia arlu/ulata, Goldf. 



Synedra vitrea, Kg. OZcistes crystallinus, Goldf. 



" scalaris, Ehr. Philodina erythropthalma, Gnldf. 



Terpsinoe musica, Ehr. Rotifer vulgaris, Schr. 



Scandium longicaudum, Elir. 



INFUSOIUA. Vorticella nebulifera, Bury. 

 Amoeba princeps, Ehr. 



Sponn'illa tluviatilis, is also abundant in Lake 



The species of Amphiprora, Bacillaria, Odontella, and Navicula, mentioned in 

 this list, are decidedly marine forms, and have been found by me on the shores 

 of the Atlantic. They also occur in estuaries ; but I confess I was surprised to 

 find them so far up the St. John's, and in company with such truly lacustrine 

 forms as many of those above mentioned. To add to the curious mixture of 

 marine and fresh-water species in Lake Monroe, I will mention that the lake 

 abounds with Paludina vivipara, Say, Ampullaria depressa, Say, with Unios, and 

 several other fresh-water molluscs, and yet contains abundance of a living 

 marine zoophyte (Campanularia,) and a large fish of the Ray family, called by 

 the settlers a " Stingaree." A curious living crustacean, a species (probably 

 new) of Sphaeroma, also abounds here, and is very destructive to cypress logs, 

 canoes, &c. Many of the silicious forms above mentioned were found in the 

 mud of the creeks leading from the immense sulphur springs near Lake Monroe, 

 and neither the Diatomacese, nor the numerous fish which inhabit these waters, 

 appear to dislike the sulphur waters. I daily saw hundreds of large gar-fish 

 which assembled directly over " the boil" of one of these springs, as if it was 

 their favorite resort ; and I also noticed that the large Amphiprora pulchra, B., 

 and the Navicula elongata, grew in great profusion in waters charged with sul- 

 phuretted hydrogen, as in the outlet of the Green Spring at Mr. Duval's. 



SHELL BANKS OF ENTERPRISE, ETC. 



The vast deposits of fluviatile shells which exist at Picolata, Volusia, and 

 Enterprise, are of great geological interest. Enterprise and Volusia present bluffs 

 and hills of forty and fifty feet in height, and extending half a mile or more 



