Occasional Papers of the Museum of Zoology 59 
Genus LicuMra (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 Elliptio (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. 
Unto recta Lamarck, ’19, p. 74 (Lake Erie). 
U. rectus Lam. = U. latissimus Raf., Conrad, ’34, p. 71; Ferussac, 
35D. 27) Manatta, “Sep. 55l © type examined): 
Unio sageri Conrad, °36, p. 53, pl. 29, f. 1 (Detroit River). 
Lampsilis recta sageri (Con.), Simpson, ‘14, p. 96 (Lake Erie and 
Detroit River). 
Eurynia recta (Lam.), Ortmann, ‘18, p. 582 (Lake Erie) ; Walker, 
"18¢, p. 184 (Lake Erie). 
LIGUMIA RECTA LATISSIMA (Rafinesque), 1820 
Type locality: Ohio River. 
Unio latissima Rafinesque, ’20, p. 297, pl. 80, f. 14-15 (Ohio River). 
Unio rectus Conrad, 736, p. 33, pl. 15 (interior drainage) (not U. 
recta Lam.). 
Lampsilis recta (Lam.), Simpson, ’14, p. 95 (Mississippi drainage). 
Eurynia recta latissima (Raf.), Ortmann, ‘18, p. 582 (interior drain- 
age) ; Walker, ’18¢, p. 184 (Ohio drainage). 
The statement of Conrad, Férussac, and Vanatta that recta 
Lam. is identical with lJatissima 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 
