70 Unizersity of Michigan 
Unio perplexus Vea, ’31, p. 112, pl. 27, £. 42. 
U. torulosus Raf.= U. gibbosus Raf.=U. perplexus Lea, Conrad, 
34, P 72. 
U. gibbosus Raf. =U. perplexus Lea, Ferussac, ’35, p. 27. 
U. gibbosus Raf.=U. torulosus Raf.—=U. perplexus Wea, Conrad, 
730,;-P 550, Dl 27, teat: 
Truncilla perplexa (Lea), Simpson, 714, p. 24. 
Tr. torulosa (Raf.) = Ambl. gibbosa Raf.—=Tr. perplexa (Lea), 
Vanatta, “15, p. 550 (“type” examined). 
Tr. torulosa (Raf.), Ortmann, ’18, p. 580. 
Tr. perplera (Lea) = A. torulosa Raf. = A. gibbosa Raf., Walker, 
*18¢, p. 186 (“if identifiable”). 
“Lea’s Unio perplexus is preoccupied by Say for a variety 
of U. ridibundus not noticed by Simpson (Am. Con., Pt. I, 
Binney s. Reprint ps 155). (Cele:As.E:) 
Rafinesque’s crude figure of A. torulosa is sufficient to rec- 
ognize in it the female of this species, since it distinctly shows 
the posterior expansion of the female shell and the character- 
istic nodes. Also the description confirms the identity. 4. 
gibbosa undoubtedly is the male belonging here, and the two 
large, nodulous ribs and the oblique furrow between them are 
unmistakable. This identification with perplerus Lea is sup- 
ported by Vanatta’s examination of the so-called Rafinesque- 
Poulson “type.” 
Conrad’s first selection (°34) of the name torulosa in pref- 
erence to gibbosa must stand, although he subsequently (’36) 
reversed this. 
DysNoMIA (DyYSNOMIA) FLEXUOSA (Rafinesque), 1820 
Type locality: Kentucky, Salt, and Green rivers. 
Obliquaria fleruosa Rafinesque, '20, p. 309. 
Unio foliatus Hildreth, ’28, p. 284, p. 16. 
Unio (Epioblasma) biloba Rafinesque, *31, p. 2. 
U. gtbbosus Raf. probably = Epioblasma biloba Raf., Ferussac, ’35, 
Pp. 27-34 (authentic specimen of biloba examined). 
U. flexuosus Raf. = foliatus Hild., Conrad, 35, p. 8, pl. 4, f. 2 (‘‘type” 
examined). 
