52 University of Michigan 
In the description of both depressa and lineolata Raf. the 
chief character of this species, great compression and posterior 
narrow and flat truncation, are mentioned, and thus there is 
no doubt about the identification. Also the peculiar color pat- 
tern is indicated in both. O. ellipsaria Raf. is also identifiable 
as this species. 
Conrad first pointed out the identity of Rafinesque’s species 
and selected the name /ineolata, and thus it has to stand. 
Genus LEPTODEA Rafinesque, 1820 
Type: Umo fragilis Raf. 
Leptodea Rafinesque, ’20, p. 295 (as subgenus of Unio), no type 
named; Herrmannsen, °47, p. 584 (type, U. fragilis Raf.), 
Lasmonos Rafinesque, ’31, p. 5 (type, fragilis Raf., ’31, not fragilis, 
20) ; Utterback, ’16, p. 151 (type, fragilis Raf., ’20; see below). 
Paraptera Ortmann, ‘II, p. 368 (type, gracilis Bar., ’23 = fragilis 
Raf., 20); Walker, ’18¢, p. 72. 
Leptodea, Frierson, ’14", p. 6 (type, leptodon Raf., ’20). 
Since U. fragilis Raf. has been made the type of Leptodea 
by Herrmannsen, Paraptera Ort. becomes a synonym having 
the same type, and the subsequent designation of U. leptodon 
Raf. as the type by Frierson becomes invalid. 
Utterback in giving as the type of Lasmonos the “Lasmonos 
fragilis Raf., ’20,’ confused Unio (Leptodea) fragilis Raf., 
‘20, and Lasmonos fragilis Raf., ’°31. The latter is not identi- 
fiable (see under Leptodea leptodon). 
LEPTODEA LEPTODON (Rafinesque), 1820 
Type locality: Lower Ohio River. 
Unio (Leptodea) leptodon Rafinesque, ’20, p. 295, pl. 80, f. 5-7. 
Anodon purpurascens Swainson, ’23, pl. 160. 
Unio velum Say, ’20, p. 293. 
Symphynota tenuissima Lea, ’29, p. 453, pl. 11, f. 21. 
Lasmonos fragilis Rafinesque, ’3I, p. 5. 
U. leptodon Raf.= Symph, tenuisstma Lea = An. purpurascens Sw., 
Conrad, ’34, p. 70. 
