Occasional Papers of the Museum of Zoology 69 
tion, for every word of it applies as well to Pleurobema pyra- 
midatum (lea): shell thick, swollen, ovate-triangular, the 
three sides curved, a light oblique and longitudinal depression ; 
epidermis nearly smooth, black; nacre rose-purplish; size 2-3 
inches. In fact, the black epidermis and the size fit U. pyra- 
midatus better than U. sulcatus. 
Thus the name obliquata cannot be revived. 
DysNoMia (PILEA) TURGIDULA (Lea), 1858 
Type locality: Cumberland River and Florence, Ala. 
Unio turgidulus Lea, ’58, p. 40 (male). 
Unio deviatus Reeve, ’64, pl. 15, f. 61 (female). 
Truncilla deviata (Rve.) (male and female) Walker, ’10°, pp. 78, 81. 
Tr. florentina (1,ea) (in part) and Tr. deviata (Reeve), Simpson. 
"14, pp. 30-31. 
Tr. curtisi Frierson and Utterback, Utterback, ’16, p. 190, pl. 6, f. 14, 
DleezSnata loo: 
Tr. turgidula (Lea) = U. deviatus Rve., Ortmann, ’18, p. 590. 
Tr. curtisi Fr. and Utt.= Tr. deviata (Rve.), Walker, ’18¢, p. 185. 
Walker (10) was the first to indicate that turgidulus Lea 
is the male of the female deviatus, by arranging his key for 
the males of Truncilla in such a way that the characters seen 
in turgidulus lead to the male of deviatus, but he did not 
expressly stated this in the text, using only the name deviata, 
while turgidulus has the priority. 
The identity of Tr. curtist from the Ozarks has been recog- 
nized by Walker (’18) and is evident from Utterback’s 
description and figures. The examination of authentic speci- 
mens distributed by Utterback has settled this beyond any 
doubt. 
DysNOMIA (PILEA) TORULOSA (Rafinesque), 1820 
Type locality: Ohio and Kentucky River. 
Amblema torulosa Rafinesque, ’20, p. 314, pl. 82, f. 11-12. 
Amblema gibbosa Rafinesque, ’20, p. 315. 
