193 ANNALS OF THE CARNEGIE MUSEUM. 
Recorded by Rhoads from the Ohio in Allegheny County. 
A dead specimen was found by the writer not far from Rhoads’ 
locality. It is found living in the Ohio in Beaver County, but is 
very rare. 
19. Plagiola (Amygdalonajas) donaciformis (Lea). 
Only two specimens are recorded by Rhoads from the Ohio River 
at Coraopolis, Allegheny County. They are in the Philadelphia 
Academy, where the writer has seen them. ‘They are both dead shells. 
This is the only one of the species previously reported, which has 
not been found by the writer. 
20. Tritogonia tuberculata (Barnes). 
Not in Harn’s, Stupakoff’s, and Clapp’s lists. Recorded by Rhoads 
from the Ohio and Beaver Rivers. 
It occurred formerly in the Monongahela at Charleroi, Washington 
County (Ehrmann Collection). The writer found several dead speci- 
mans in Dunkard Creek, Greene County, and live ones in the Ohio in 
Beaver County, and at various places in the Mahoning and Shenango 
Rivers, and Pymatuning Creek in Lawrence and Mercer Counties. 
According to Sterki (Nautilus, 21, 1907, p. 48) this species has all 
four gills charged in the breeding season (June 10, 1907). ‘This will 
remove it, in our final arrangement, into the genus Quadruda, 
and then the name of the species must be changed, on account 
of the existence of the species of Quadrula named tuberculata 
by Rafinesque. None of the synonyms is available: U. pustulata 
Swainson (1840) being preoccupied by U. pustulatus Lea (1834), 
and U. gigas (Swainson) Sowerby (1867) being not this species, but 
equivalent to Wyriopsts cumingt (Lea) (see: Frierson, Nautilus, 21, 
1907, p. 49). Thus we are forced to apply a new name, and Quad- 
rula tritogonia nom. nov. is proposed. (See Nautilus, 22, 1909, 
Dev DOT ) 
21. Cyprogenia irrorata (Lea). 
Not mentioned in any of the previous lists, except in that of Rhoads, 
who reports it from the Ohio, at Beaver. 
The present writer has found only dead shells in the Allegheny 
River in the northeastern corner of Allegheny County, and in the 
southern part of Armstrong County. 
22. Obliquaria reflexa Rafinesque. 
First indicated from Allegheny County by ‘Clapp (UW. cornutus), 
then by Rhoads from the Ohio River in Allegheny and Beaver Counties. 
