16 



SYNOPSIS OF 



O 



I— I 



O 

 l^i 



>H 



;>- 



I 



o 



SUBROTUND. 



Unio verrucosus albus. Say; but not of Hil~ 

 dreth* 



turgidus. Lea. 



Unio Mortoni. Con. 



Cooperianus. Lea. 



verrucosus. Bar. Eat. 

 Unio tuberculata? Raf. 

 Unio tuberculosa. Valen. 

 Unio verrucosus purpureus. Hild, 

 Unio tuberculatus. Con. 



nodulosus. Lea. 



Mya nodulosa.t Wood. Dill. 



irroratus. Lea. Eaton. 



Unio verrucosus albus. Hild. 



dromas. Lea. 



* A specimen sent to me by Dr. Hildreth as TJnio verrucosus albus, proved 

 to be a true irroratus, (nobis.) 



•j- This shell, as figured by Wood in his " General Conchology," seems to 

 me to be distinct from the pnstulosus, (nobis,) with which it has been con- 

 founded. The figure of Wood is longer than any pustulosus I have seen, 

 and the epidermis is much darker, (" bottle green.") The nodules are more 

 numerous about the beaks, and the lateral tooth is longer and thicker, I 

 doubt if the nodulosus be an American species.* 



