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ANNALS 



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PHILOSOPHY. 



OCTOBER, 1825. 



Article I. 



Observations on the Sipiojuma of the Genera Anomia, Crania 

 Orbicida, and Discina. By J. E. Gray, Esq. FGS. &c. 



-\ (To tlie Editors of the Annals of Fhilosophy.) 



y^. GENTLEMEN, British Museum, Sept. 12, 1825. 



■■: LiNNJLUS, ill his Systema Naturse, has formed a genus with 

 the following characters, " Animal corpus hgula, emarginata 

 ciliata, ciliis valvulae superiori affixis: hrachiis 2, linearibus, cor- 

 pora longioribus, conniventibus, porrectis, valvultie alternis, 

 utrinqueciliatis, ciliis affixis valvulis utrisque. Te5^« ineequivalvis ; 

 valvula altera planiuscula, altera basi magis gibba, harum altera 

 S8epe basi perforata. Cardo edentulus, cicatricula lineari pro- 

 niinente introrsum dente laterali ; valvules vero planioris in ipso 

 margine. Radii duo ossei pro basi animalis." This genus he 

 has called Anomia, a name most probably derived from the 

 specific titles of the Concha anomia of Fabius Columna, and 

 the Pectunculus anomius of Dr. Lester, which appear intended 

 to have been expressive of the inequality or dissimilarity of the 

 valves of those shells. 



The above character of the animal agrees exactly with that 

 given by Cuvier to a group of Mollusca, which he cjills Bra- 

 chiopoda, from the belief of their ciliated arms being the 

 modified feet of the Conchophorus Mollusca ; and the descrip- 

 tion of the shell, on account of the larger valve being said to 

 be gibbous and perforated in the hinder part, and the inside of 

 one of the valves being furnished with two bony rays, must have 

 been taken from one of those shells which Bruguiere has since 

 formed into a genus, under the name of Terebratula ; a word 

 most likely derived from Linnaius, who uses it as a specific 

 name for one of the species which belong to this section of his 

 genus. 



Linnaeus, from not knowing the animal, has placed several 

 ISlew Series, vol. x, n 



