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141 I 



TERTIARY FAUNA OF FLORIDA 



slightly for a byssus, and resembles a species of the section Glans. Gray in 

 1854 referred the genus to Mytilicardia. When the valves are closed the shelly 

 infold of the female is completely included within them. It is formed from 

 the inner layer of the shell alone, and is lined by a fold of the mantle. The 

 eggs are discharged into it and remain until the young shells have progressed 

 beyond the prodissoconch stage. 



Genus Milneria Dall, 1881. Type Ceropsis miiiiina Dall, 1871. Recent. Cali- 

 fornia. 



Shell with two left and three right cardinals, the posterior left lateral, 

 posterior and anterior right cardinals minute and hardly recognizable except 

 in very well-developed specimens, in which the formula is ^- '"'"i"- . The female 

 has a dome-like indentation rising from the ventral margin of the valves, which 

 is closed only by an extension of the mantle edge and therefore not included 

 within the shut valves. The animal is minute, byssiferous, and a nestler on 

 flat surfaces, like the backs of the shells of Haliotis. 



The name Ceropsis being preoccupied in Coleoptera by Solier in 1839, it 

 was replaced by Milneria. The young appear to be incubated in the same 

 manner as in Thecalia. 



Genus OARDITA (Bruguiere) Lamarck. 

 Chama (sp.) Linne, Syst. Nat., ed. x., p. 691, 1758. 

 Trapezium (sp.) anonymous. Cat. Calonnianum, p. 50, 1797. 

 Corbula (sp.) Bolten, Mus. Bolt., p. 185, 1798; not of Bruguiere. 

 <^Cardita Bruguiere, Enc. Meth., i., p. 401, 1792. 

 Cardita Lamarck, Prodrome d'un Nouv. Class. Coq., p. 86, 1799; sole ex. C. calyculata 



Bruguiere. 

 Arcinella (pars) Oken, Lehrb. d. Naturg., pp. viii., 236, 238, 1815 ; not of Schumacher, 



1817. 

 Cardita ji Schumacher, Essai, p. 141, 1817. 

 Les mytilicardes Blainville, Diet. Sci. Nat., xxxii., p. 326, 1824; Morch, Cat. Yoldi, ii., 



p. 38, 1853 (in syn,). 

 Mytilicardita Anton, Verzeichn., p. 10, 1839 ; Morch, Cat. Yoldi, ii., p. 38, 1853. 

 Jesonia Gray, Synops. Brit. Mus., 1840; P. Z. S., 1847, p. 194. 

 Mytilicardia Herrmannsen, Index Generum Mai., ii., p. 83, 1847; Gray, Ann. Mag. N. 



Hist, xiv., p. 22, 1854 {ex parte) ; Tryon, Proc. Acad. Nat. Sci. Phila., p. 255, 1872. 

 Mytilocardia Agassiz, Nomenclator, p. 704, 1847. 

 Jesonia Philippi, Handbuch d. Mai., p. 462, 1853. 

 Not Cardita Morch, Cat. Yoldi, ii., p. 38, 1852, = Isocardia Lam. 



