720 i'ii<>fi-;i:i>ix<;s OF THE X.ITIOX IL Mrsi>;rM. VOL.XXH. 



t UNIO AMABILIS Lea. 



*rio amahilis LKA, Pr. Acad. X. Sci. Phila., IX, 1865, p. 89; * Jl. Acad. N. Sci. 

 Phila., VI, 1869, p. 257, pi. xxxi, fig. 72; *Obs., XII, 1869, p. 17, pi. xxxi, 

 fig. 72.* B. H. Wright, Check List, 1888. 



* Margaron (Unio) amabilis LEA, Syn., 1870, p. 37. 



Butler, Taylor County, Georgia; North Carolina? 



UNIO SUBPLANUS Conrad. 



I'nio xitbplatiHs CONRAD, Monog., IX, 1837, p. 73, pi. XLI, fig. 1; * Pr. Ac. N. Sci. 

 Phila., VI, 1853, p. 258.* HANLEY, Biv. Shells, Snpp., 1856, p. 383, pi. xxi, 

 fig. 16. *H. and A. ADAMS, Gen. Rec. Moll., II, 1857, p. 493. *KUSTER, 

 Conch. Cab. Uuio, 1862, p. 272, pi. xci, fig. 5. *B. H. WRIGHT, Check List, 

 1888.* P.ETEL, Conch. Sam., Ill, 1890, p. 168. 



* Margaron (Unio) subplanus LEA, Syn., 1852, p. 33; 1870, p. 54. 



*Unio subplannm SOWERBY, Conch. Icon., XVI, 1866, pi. XLVII, tig. 252. 



North Carolina and Virginia. 



UNIO BRIMLEYI S. H. Wright. 



*Unio brimleyi S. H. WRIGHT, Naut., X, 1897, p. 138; * SIMPSON, Pr. Ac. N. Sci. 

 Phila., 1900, p. 80, pi. iv, fig. 6. 



Neuse River and Irwin's Creek, North Carolina. 

 (Group of Unio complanatus.) 



Shell elongate trapezoidal, moderately solid, but little inflated, nearly 

 straight below, with a posterior ridge, usually biangulate behind; 

 beaks not prominent, sculptured with several coarse, parallel ridges 

 which follow the growth lines or are nearly straight. Epidermis some- 

 times shining and feebly rayed, becoming rough and rayless with age; 

 laterals straight or slightly curved; beak cavities shallow. 



Animal with the marsupium occupying all or nearly all of the outer 

 branchiaB; gills long, rounded below, inner much the larger, free nearly 

 or quite their whole length from the abdominal sac. 



t UNIO COMPLANATUS (Solander) Dillwyn.i 



Mya complanata SOLANDER, manuscript (no date). * PORTLAND catalogue, 1786, 

 p. 100, Lot 2190.* DILLWYN, Cat., I, 1817, p. 51. 



* Unio complanata DESHAYES, An. sans Vert., 2d ed., VI, 1835, p. 559; 3d ed., II, 



1839, p. 676. 



1 This species was described by Solauder in Latin, but the manuscript was never 

 published and is now in the British Museum. Mr. Edgar A. Smith kindly examined 

 it for me and informed me that Dillwyn's description in the catalogue is a transla- 

 tion from Solander. The name Mya complanata was used by Lister in Hist. Sive. 

 Conch. (1770, p. 150), but Lister was not a binomial author. The Portland catalogue 

 is anonymous, and a mere sale list. I have done my best to straighten out the syn- 

 onymy of this variable and exceedingly puzzling group, and have examined nearly 

 all the types and a great amount of material. In some cases, as in the Buckleyi 

 group, there seem to be no specific lines whatever. 



