1 86 Bryant Walker 



Truncilla brkvidens (Lea). 



Vanatta (140, p. 550) states that the shell in the Poulson collection la- 

 belled Obliqiiaria interrupta Raf. is this species. If identifiable from the 

 original description, Rafinesque's name has precedence. 



Truncilea perplexa (Lea). 



This species has been identified by Conrad and others as Aniblciiia torii- 

 losa Raf. and Amhlcma gibbosa Raf. According to Vanatta (140, p. 550) 

 the shells so labelled in the Poulson collection are this species. Either 

 name, if identifiable from the original description, would have priority. 



Truncilla sulcata (Lea). 



Unio sfczvardsovi stcvcnsoni De Gregorio, Moll, di aq. dul. di Amer., 1Q14,. 

 p. 15, pi. \'I, fig. 3. 



Un'w propesiilcatiis De Gregorio, Ibid, p. 30, pi. X, fig. 2. 



Vanatta (140, p. 550) states that the shell in the Poulson Collection 

 under the name of Obliqiiaria obliquafa Raf. is this species. If identifiable 

 from the original description, it would take precedence. 



Truncilla triouEtra Rafinesque. 



Unio triangularis pergibbosa De Gregorio, ]\Ioll. di aq. dul. di Amer., 1914, 



p. io,.pl. II, fig. 4. 

 Unio triangularis longiusculus De Gregorio, Ibid, p. 10, pi. TI, fig. 5. 



Truncilla triquktra triangularis (Barnes). 



Barnes' types of his Unio triangularis rame from Bois Blanc Island in 

 the Detroit River and the form is fairly entitled to varietal rank, being like 

 nearly all of the Uniouidcc of the Great Lakes a characteristically depauper- 

 ate race. 



Truncilla walkEri Wilson and Clark. 



Truncilla ivalkcri Wilson and Clark, Bur. of Fish. Doc. No. 781, 1014, p. 



46, pi. I, fig. I. 

 Type locality: East Fork of Stone's River, Walterville, Tenn. 



Subgenus DYSNO^IIA Agassiz, 1852. 



Frierson (42, p. 7) identifies Rafinesque's Unio or Hpioblasma biloba 

 with 7'. foliata (Hild.) and consequently replaces Agassiz' subgeneric name 

 by Bpioblasvna Raf. 



