54 (Jnhcrsity of Michigan 



Paraptera fragilis {Raf.)=[7. gracilis Bar.. Ortmann, 'i8, p. 572. 

 Lamp, gracilis (Bar.) = L^ fragilis Raf., '20^: Lasmonos fragilis 

 Raf., '31; Walker, 'i8c, p. 182 ("if identifiable"). 



The description of U. fragilis, chiefly its comparison with 

 U. Icptodon, makes it sure that this is the gracilis Bar. The 

 shell is thin, fragile, not elongate and attenuated posteriorly 

 (as leptodon is), but somewhat dilated behind. Also the char- 

 acters of the pseudocardinals are mentioned. 



It remains doubtful whether Lasmonos fragilis is this shell 

 or Leptodca Icptodon (see under the latter). 



Genus Caruncuuna Simpson, 1898 

 Type: Unio parvus Barnes. 



To.volastna Rafinesque, '31, p. 2 (no type named). 



Coruiiculina Simpson, '98, p. 109 (error typographicus) (only spe- 

 cies, U. parvus Bar.). 



Carunculina Simpson, 'co •. p. 563. and '14. p. 148 (type. Unio tcx- 

 asensis Lea). 



Toxolasma Raf., Frierson, '14", p. 7 (type, lividus R-ii. ^i: glaiis 

 Lea) ; Ortmann, '18. p. S72. 



The revival of the generic name Toxolasma depends upon 

 the identity of U. lii'idus Raf. As will be shown under Car. 

 fiiocsta, lii'idns is not recognizable, and thus the name Toxo- 

 lasma should be discarded. 



As type of Carunculina. U. parvus must be taken, for at the 

 first ptiblication of this subgenus only this species was inchided. 



Carunculina mcesta (Lea), 1841 



Type locality: French Broad River, East Tennessee. 



Unio (Toxolasma) lividus Rafinesque, '31, p. 2. 

 Unio pullus Conrad, '38, p. 100, pi. 55, f. 2. 

 Unio niccsttis Lea, '41, p. 82. 

 Unio cylindrcllus Lea, '68, p. 144. 

 Unio corvimcubis Lea, '68, p. 144. 



Unio glans Pilsbry and Rhoads, '96. p. 502 (not glans Lea, "34). 

 Lampsilis cylindrella (Lea), L. masta (Lea), L. corzninculus (Lea), 

 L. pullus (Con.), Simpson, '14, pp. 155-160. 



