ANODONTA. 155 



ANODONTA, Brugieue. 



Shell equivalve, ovate, usually rather thin, aurleulated, 

 inequilateral, closed. Beaks small. Hinge without teeth, 

 but furnished with a lamina. Ligament external, linear. 

 Pallial impression simple. 



Animal oblong, mantle freely open, with simple margins 

 in front and anteriorly, but fringed with numerous short 

 cirrhi in the branchial region, plain in the anal. Foot large, 

 broad, compressed. Labial palps large, lanceolate. 



Like Unio this genus is chiefly American, only one dis- 

 tinctly-marked species inhabiting Europe. The animal 

 is very prolific. Li spring and summer the branchial 

 leaflets of the female of our native Anodonta may be found 

 charged with minute, yet complete, shelled young ones, to 

 the number of many thousands ; and Mr. Lea of Philadel- 

 phia, a naturalist who has done much towards the elucida- 

 tion of the tribe, has calculated as many as six hundred 

 thousand young Anodontas to be present in a single adult 

 specimen three inches long. 



A. CYGNEA, Linnseus. 



Plate XXXIX. fig. 3, XL. figs. 2 and 3, and XLI. and (animal) Plate Q. fig. 3. 



* Mytilus cygneus, Linn. Syst. Nat. ed. 12, p. 1 158 Da Costa, Brit. Conch. 



p. 214. — Mont. Test. Brit. p. 171. — Maton and Rack. 

 Linn. Trans, vol. viii. pi. 3 A, f. 2. — Turt. Conch. Diet, 

 p. 115. — ScHROTER, Einleit. Conch, vol. iii. p. 440. — Poli, 

 Test. Sicil. vol. ii. p. 212, pi. 33, f. 1, 2.— Sheppard, Trans. 

 Linn. See. vol. xiii. pi. 5, f. 3. — Dillwyn, Recent Shells, 

 vol. i. p. 315. — Fleming, Encyclop. Edin. vol. vii. pi. 205, 

 f. 16. 

 „ anatinus, Linn. Syst. Nat. p. 1158. — Turt. Conch. Diction, p. 116. — 



For additional synonyms see varieties. 



