HETEROGANGLIATA. 



Invertebrated Animals. 



No. 14. 

 OSTREA EDULIS. 



COMMON EDIBLE OYSTER. 



Testce Ostrece. 



The animal substance. A medicinal agent. 



The Shell 



Geog. Position. European and Indian seas. 



Quality. Delicious, digestible. 



Power. Aphrodisiac, lithontriptic. 



Use. Aliment, phthisis, and some abdominal affections. 



SCIENTIFIC ANALYSIS. 



Natural Classification. 

 4. DIVISION Heterog'ang'liala. CLASS Conchifera. 



Ballardand Garrod, Mat. Med. 453. Syst. Nat. Gmelin, VI. 3315. Pereira, Mat 

 Med. II. 769. Thompson, Mat. Med. *71. Lond. Disp. 466. U. S. Disp. 735. EC. 

 Disp. U. S. 146. Jones, An. King. 379. Wyatt, Nat. Hist. 107. 



GENUS OSTREA. 



Ecailles de Huitres (Er.), Austerschaalen (Ger.), Conchiglia d'ostrica (It.), 

 Cascara (Sp.). 



THE ESSENTIAL CHARACTERS. 



Mollusks, acephalous, aquatic, with a bivalve or multivalve 

 shell. The mantle opens in various ways, sometimes before, 

 sometimes all around, and then again only upon one side. 



Organs of respiration four pectinated laminae. 



Heart simple. Touch and taste the only senses certainly 

 ascertained to exist. 



Feet very small or entirely wanting. 



THE SECONDARY CHARACTERS. 



OSTREA. Body compressed, more or less orbicular. Edges 

 of the mantle thick, non-adherent or retractile, and provided 

 with a double row of short and tentacular filaments. The 

 two pair of labial appendices triangular and elongated. A 

 subcentral, bipartite muscle. Shell irregular, inequivalved, 



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