300 ORTMANN—CORRELATION OF SHAPE AND 
Unio striatissimus Anthony, ’65 (Tennessee). 
Dia. 30 per cent. 
Unio planior Lea, ’68 (Tennessee; Holston R., Washington Co., 
Va.).—Pleurobema planius Simpson, ’14, p. 302. 
Dia. (Lea) : 35 per cent.; (Simpson) : 33 per cent. 
Unio brevis Lea, ’72 (Conasauga Cr., Monroe Co., Tenn.),—Pleuro- 
bema breve Simpson, ’14, p. 800. 
Dia. (Lea) : 35 per cent.; (Simpson) : 36 per cent. 
Unio swordianus Wright, ’97 (Powell R., Lee Co., Va.).—Pleuro- 
bema sword. Simpson, 14, p. 757. 
Dia. (Simpson): 40 per cent. These measurements are taken 
from an extremely obese specimen. Other specimens in the original 
lot all fall below 40 per cent. 
3. PLEUROBEMA OVIFORME HOLSTONENSE (Lea).—Dia. 50 per 
cent. or over. 
Unio holstonensis Lea, ’40 (Holston R.).—Pleurobema holst. Simp- 
SOn, 24./p. 730. 
Dia. (Lea) : 54 per cent.; Simpson) : 50, 56, 58 per cent. 
Unio mundus Lea, 57 (Tennessee R., Ala.) —Synonym to holston- 
ense, according to Simpson. 
Dia: (lea;) 64 per cent. 
Unio tesserule Lea, ’61 (Nolichucky R., Tenn.).—Pleurobema tess. 
Simpson, 714, p. 749. 
Dia. (Lea and Simpson) : 64 per cent. 
Unio pattinoides Lea, ’71 (Clinch and Holston).—Synonym to 
holstonense, according to Simpson. 
Dia; (Gea)<'51 percent. 
Unio acuens Lea, ’71 (Tennessee R., Concord, Tenn.).—Pleuro- 
bema acuens Simpson, ’14, p. 746. 
Dia. (Lea): 55 per cent. Simpson’s measurements give 48 per 
cent., and thus belong to typical oviforme. 
Unio lawi Lea, ’71 (Tennessee R., Tuscumbia, Ala., Holston R.) — 
Synonym to holstonense, according to Simpson. 
Dia. (Lea): 56 percent. 
Unio bellulus Lea, ’72 (Holston R.; Tennessee R., Mussel Shoals, 
Ala.).—Synonym to holstonense, according to Simpson. 
Dia. (Lea) : 64 per cent. 
