20 



SYNOPSIS OF 



o 



z 



K 

 S 

 w 



O 



s 



OVAL. 



*Nashvillianus. iea. 



*Zeiglenanus. hm. 



lienosus. Con. 



*obscurus. Lea. 



*delodontus. Lam. 



Unio lacteolus. iea. D'Orb. 



*charruaaus.t B^Orb. 



*lamellatus. Lea. 



*Bengalensis. Lea. 



*coeruleus. Lea. Ben. 



*olivarius. Lea. Ben. 



*Batavus. Lam. 

 Mya pictorura 



Monla. 

 Myaovalis.l Soland. 

 Mya Batava. Wood. Maton 

 Mysca Batava. Turton. 

 Unio liparia. Pfeif. 

 Unio pictorum. Drap., pi. II, fig. 3 



Pfeif. Flem. 

 Chem. SchrOeter. 



Bill. 



OVAL. 



Unio fusculus. Milhl. 

 Unio gibba. Miihl. Pfeif. 

 Unio Labacencis. Miihl. 

 Unio reniformis. Schmidt. 

 Unio fuscus. Zeig. 

 Unio consenlaneus. Zeig. 

 Unio amnicus. Zeig. 

 Unio carynlhiacus? Zeig. 

 Unio decurvatus. Rossmaesler, 

 Unio sinuatus. Stud. 

 Unio planus. Stud. 

 Unio aier.§ JW7. 



g *Cunibeilandianus. Lea. 

 2 -^ 



Smilhii-ll Gray. 

 vibex. Con. 



*Muhlfeldianus. Lea. 

 *creperus. Lea. 

 *glaber. Lea. 



*Hildietliianiis.^r Lea. 

 Al. ambigiia 1 Say. 



*fabalis."ft Lea. 



t The two specimens sent to me by M. D'Orbigny are so like delodontus, that I am strongly induced to 

 believe that they will prove to be the young of that species. 



X On the authority of Dillwyn. 



§ On the authority of Ferussac. 



II Never having seen this shell, I place it here on the authority of Mr Gray. — See his figure in GrifTith's 

 Cuvier, Vol. XII. 



^ I retain this species among the Uniones, although it does not possess a perfect lateral tooth. As it is, 

 however, thickened along the dorsal margin, and puts on the appearance of a tooth, I have concluded that it was 

 better not to remove it to the Sub. Gen. Margaritana, to which it has little resemblance in its general characters. 

 These observations may apply to U. oriens (nobis), and partially to U. monodonta. Say, [U. solenifornus, 

 nobis.) Mr Say's description of amhigua answers well to Hildrelhianus, but I am not sure it is the same, as 

 he has given no figure of it. He seems to have abandoned it, as he does not insert it in his " Synonymy." 

 Mr Conrad also avoids the insertion of it in his Synoptical Table. 



tt Say and Conrad both in their catalogues give precedence to lapillus. Fahalis is in my Memoir read 

 before the Am. Philos. Soc, May 7, 1830, and inserted in the Transactions ; capilhts was first inserted in the 



