Occasional Papers of the Museum of Zoology 19 
designated O. subrotunda as the type of this genus, which 
makes Rotundaria the same as Obovaria as used by Simpson 
(type, U. retusa Lam., congeneric with O. subrotunda Raf.). 
See Obovaria. No other name being available for the present 
genus, Dr. Pilsbry has suggested that of “Cyclonaias,” which 
we adopt here with the type given above. 
PLETHOBASUS CyPHYUS (Rafinesque), 1820 
Tvpe locality: Falls of the Ohio at Louisville, Ky. 
Obliquaria cyphya Rafinesque, ’20, p. 305. 
Unio esopus Green, 27, p. 46, f. 3. 
Unio cyphia Raf. =U. esopus Green=U. cicatricosus Say, ’29= 
U. varicosus Lea, ’29, Conrad, ’34, p. 68. 
U. cyphia Raf.=U. @sopus Green, Ferussac, ’35, p. 27. 
U. cyphyus Raf., Call, ’o00, p. 496. 
Pleurobema cyphia (Raf.) =Pl. @sopus (Green), Vanatta, ’15, p. 
550 (‘“type’ examinel). 
Obl. cyphya Raf. = Pleur. esopus (Green), Walker, ’18¢, p. 181 (“if 
identifiable” ). 
Plethobasus cyphyus (Raf.), Ortmann, ’19, p. 65. 
The chestnut-brown color of the epidermis, the flexuous 
border of the shell, the thick oblique rib of the disk with a few 
tubercles, characters given in the original description, undoubt- 
edly indicate this species, as maintained by Call. Thus the 
name cyphya (not to be spelled cyphia) stands. 
LEXINGTONIA DOLABELLOIDES (Lea), 1840 
Type locality: Holston River, Tennessee. 
Unio dolabelloides Lea, ’40, p. 288. 
Pleurobema dolapelloides (Lea), Simpson, ’14, p. 752. 
Lexingtonia dolabelloides (Lea), Ortmann, "18, p. 545. 
LEXINCTONIA CONRADI (Vanatta), I9Q15 
Type locality: (maculatus Conrad ) Elk and Flint rivers, 
tributaries of Tennessee in Alabama. 
Unio maculatus Conrad, ’34, Pp. 30, pl. 4, f. 4 (not Unio nigra 
maculata Raf., ’20). 
