Occasional Papers of the Museum of Zoology 59 



Genus Ligumia (Swainson), 1840 

 Type: Unio recta Lam. 



Eurynia Rafinesque, '20, p. 297 (no type named) ; Herrmannsen, '47, 

 p. 564 (type, U. dilatata Raf.) ; Agassiz, '52, p. 45 (type, U. recta 

 Raf.) ; Simpson, '00. p. 534 (type, U. recta Lam.). 



Ligumia Swainson, '40, p. 378 (type, recta Lam.). 



The first designation of a type for Eurynia was that of U. 

 dilatata Raf. by Herrmannsen, and thus Eurynia becomes a 

 synonym of ElUptio (which see). This opens the way for the 

 admission of Ligumia Swainson with the same type as Eurynia 

 of Agassiz and Simpson. 



Ligumia recta (Lamarck), 1819 

 Type locality: Lake Erie. 



Unio recta Lamarck, '19, p. 74 (Lake Erie). 



U. rectus Lam. = U. latissiinus Raf., Conrad, '34, p. 71 ; Ferussac, 

 '35. P- 27; Vanatta, '15, p. 551 ("type" examined). 



Unio sagcri Conrad, '36, p. 53, pi. 29, f. i (Detroit River). 



Lampsilis recta sagcri (Con.), Simpson, '14, p. 96 (Lake Erie and 

 Detroit River). 



Eurynia recta (Lam.), Ortmann, '18, p. 582 (Lake Erie) ; Walker. 

 'i8c, p. 184 (Lake Erie). 



Ligumia recta latissima (Rafinesque), 1820 

 Type locality: Ohio River. 



Unio latissima Rafinesque, '20, p. 297, pi. 80, f. 14-15 (Ohio River). 



Unio rectus Conrad, '36, p. 33, pi. 15 (interior drainage) (not U. 

 recta Lam.). 



iMmpsilis recta (Lam.), Simpson, '14, p. 95 (Mississippi drainage). 



Eurynia recta latissima (Raf.), Ortmann, '18, p. 582 (interior drain- 

 age) ; Walker, 'i8c, p. 184 (Ohio drainage). 



The statement of Conrad, Ferussac, and Vanatta that recta 

 Lam. is identical with latissima is correct only when we do 

 not separate these two forms, but if they should be separated 

 as varieties, recta Lam. refers to the Lake Erie form, which 

 is evident not only from the locality given but also from the 



