1G1 



U. obesus, (Lea.) Trans. Am. Phil. Soc. vol. 

 4, pi. xiii. f. 26. 

 incurvus, do. do. pi. xiii. f. 27. 



anodontoides, do. do. pi. viii. f. II. 



glans, 



elegans, 



ebenus, 



asper, 



fabalis, 



soleniformis, 



acutissimus, 



olivarius, 



do. do. pi. viii. f. 12. 



do. do. pi. ix. 13. 



do. do. pi. ix. 14. 



do. do. pi. ix. 15. 



do. do. pi. x. 16. 



do. do. pi. x. 17. 



do. do. pi. x. 18. 



do. do. pi. xvi. 38. 



U. pyramidatus, (Lea.) Trans. Am. P. Soc. 

 vol. 4, pi. xvi. f. 39. [White var. Un- 

 datus of Barnes.] 

 ' trigonus, (L.) T. A. P. S. v. 4, p. xvi. f. 40. 

 ' formosus, do. do. pi. xvi. 41. 

 ' perplexus, do. do. pi. xvii. 42. 

 ' foliatus, (Hildreth.) Sil. J. vol. 14. 



' angustatus,(L.)T.A.P.S.v.4,p.xvii.f.43. 

 ' arcaformis, do. do. pi. xvii. f. 44. 

 ' ochraceus, (Say.) Nich. Ency. pi. ii. f. 8. 

 ' crassa, Say's Am. Cone. pi. i. f. 8. and 

 Wood's Gen. Cone. pi. xx. xxi. 



Hyria. Shell equivalve, obliquely triangular, eared; the base truncated 

 and straight; hinge with two low teeth; the posterior or cardinal one divided 

 into numerous diverging parts, of which the interior are the smallest, the oth- 

 er anterior or lateral, very long and lamellar. Ligament external, linear. 

 H. avicularis, H. corrugata. 



Anodonta. Shell equivalve, inequilateral, transverse; hinge linear, with- 

 out teeth: a smooth, cardinal lamina, truncated, or forming a sinus at its an- 

 terior extremity, terminates the base of the shell. Two distant, lateral sub- 

 geminal, muscular impressions. Ligament linear, external; its anterior 

 extremity inserted in the sinus of the cardinal lamina. 



A. maximus, (a new species, from Lake A. cataracta, (Say.) Am. C. pi. iii. f. 4 



Superior,) — nondescript, 

 undulata, (Say.) Rugosus of Swainson, 



an old shell, 

 suborbiculata, (Say.) Am. Cone. pi. xi. 

 areolatus, (Swainson.) Illus. of Zoology, 

 cygnams, (Lamarck.) Brewster's Cyclop. 



vol. 8, pi. ccv. f. 16. 

 anatina, (Lamarck.) Turton's Biv. Shells, 



and Pennant's Zoology, pi. lxviii. f. 79. 

 sulcata, Ency. Meth. pi. ccii. f. 1. a. b. 



A.marginata of Say, Am. C. pi. iii. f. 5. 



' rubens, Ency. Meth. pi. cci. f. ]. a. b. 



hab. Senegal, 

 crispata, do. pi. cciii. f. 3. a. b. do. 

 uniopsis, (South Seas.) 

 intermedia, Encyc. Meth. pi. cci. f. 2. 



hab. France, 

 trapezialis, (this may be the undulatus of 



Hildreth.) 

 glauca, (hab. Acapulco.) 

 sinuosa, Ency. Meth. pi. cciii. f. 2. a. b. 

 Patagonica, do. pi. cciii. f. 1. a. b. 



Iridina. Shell equivalve, inequilateral, transverse; the beaks small, 

 reflected, almost straight; muscular impressions similar to the genus Anodon; 

 hinge long, linear, attenuated about the middle, tuberculated throughout the 

 whole length, almost crenated; the tubercles unequal, frequent. Ligament 

 external, marginal. 



I. Nilotica, (Sowerby.) Zool. Jour. 



I. exotica, Ency. 204. 



21 



