HO. 1205. syyorsm OF THE NAIADES SIMPSON. 533 



tLAMPSILIS DOLIARIS Lea. 



Unio doliaris LEA, Pr. Ac. N. Sci. Phila., XVII, 1865, p. 88; Ml. Ac. N. Sci. Phila., 

 VI, 1868, p.260. pi. xxxn, tig. 75; *Obs., XII, 1869, p. 20, pi. xxxn, fig. 75. 



* B. H. WRIGHT, Check List, 1888. 



* Margaron ( Unio) doliaris LEA, Syn., 1870, p. 42. 



Alabama and Tombigbee drainage. 



fLAMPSILIS BREVICULUS Call. 



* Unio breviculus CALL, Pr. U.S.Nat. Mus., X, 1887, p. 499, pi. xxvin; * Tr. Ac. 



Sci. St. Louis, VII, 1895, p. 6, pi. xvn. 



tLAMPSILIS BREVICULUS var. BRITTSI Simpson. 

 *Lamp8ili8 brittsi Simpson, Pr. Ac. N. Sci. Phila., 1900, p. 76, pi. v, figs. 1, 2.' 

 White and Current rivers, Arkansas; Texas County, Missouri. 



tLAMPSILIS BIANGULATUS Lea.- 



* Unio biangulatus LEA, Pr. Am. Phil. Soc., 1, 1840, p. 288 ; * Tr. Am. Phil. Soc., VIII, 



1843, p. 197, pi. ix, fig. 8; * Obs., Ill, 1842, p. 35, pi. ix, fig. 8.* CONRAD, Pr. 

 Ac. N. Sci. Phila., 1853, p. 245. *CHENU. 111. Conch., 185S, pi. xxx, figs. 

 7, la, 7b. *H. and A. ADAMS, Gen. Rec. Moll., II, 1857, p. 492. * KUSTER, 

 Conch. Cab. Unio, 1861, p. 189, pi. LX, fig. 1; pi. LXI, fig. 1. *SOWERBY, 

 Conch. Icon., XVI, 1868, pi. LXXX, tig. 421.* B. H. WRIGHT, Check List, 

 1888.* P^TEL, Conch. Sam., Ill, 1890, p. 146. 

 Margaron ( Unio) biangulatus LEA Syn., 1852, p. 38, 1870, p. 61. 



Tennessee drainage. 



LAMPSILIS SUBVEXA Conrad. 3 



*Anodonta subvexa CONRAD, Am. Jl. Sci., XXV, 1834, p. 341, pi. I, fig. 1 ; *New F.W. 

 Shells, 1834, p. 73.* FKRUSSAC, Guer. Mag. 1835, p. 25. *MSLLER, Syn. Nov. 

 Gen., 1836, p. 194. * CONRAD, Pr. Acad. N. Sci. Phila., VI, 1853, p. 264. 



* H. and A. ADAMS, Gen. Rec. Moll., II, 1857, p. 503. *B. H. WRIGHT, Check 

 List, 1888.* P.ETEL, Conch. Sam., Ill, 1890, p. 185. 



1 At the time I published the L. brittsi I believed it to be a valid species. Since 

 then I have seen additional material which seems to be a connecting link between 

 it and L. brericttlus. I can not be certain as to the relationships of this form, which 

 seems on the one hand to have characters belonging to the typical section of Lamp- 

 silis and on the other to be related to L. spatulatits and L. pleasi. 



' 2 The systematic position of this species is a little uncertain. In the form of the 

 shell and the teeth it seems to belong in the Ventricosu* group, but the texture and 

 broken rays apparently ally it to the Ligamentinu* group. The soft parts agree best 

 with those of members of the former assemblage, so I place it here. 



3 I do not know what this is, nor where it belongs, but it is certainly not a true 

 Anodonta. The shell, according to Conrad's figure, is rayed throughout, and looks 

 very much like a young U.ventricosus. He says that it has a callus resembling an 

 incipient tooth; that it inhabits the Black Warrior River, and that it is very rare. 

 It is just possible that it is related to some of the so-called Margaritanas of the 

 Southern States, such as M. spillmani, but I think it more likely some young form of 

 the I'r.iiirint8nn group in which the hinge has been injured. I place it here with the 

 greatest hesitation. 



