THE NAUTILUS. 45 



any doubt as to the correctness of his new classification or that 

 in any degree he intended to impugn its validity. 



If I am right in this contention, much of the tentative syno- 

 nymy proposed by Mr. Vanatta will have to be reviewed. 



In view of the fact that the adequacy of Rafinesque's original 

 descriptions is expressly left in abeyance, it would seem to be 

 better to retain the Simpsonian names until all of those ques- 

 tions can be definitely determined. 



Expressly reserving, therefore, all questions relating to the 

 adequacy of Rafinesque's original descriptions and simply to 

 determine "the effect on nomenclature if they were recognized 

 and the names dated from 1820," taking the species in the 

 order given by Vanatta, it would appear to be necessary to make 

 the following changes : 



Truncilla. brevidens Lea. 



Described by Rafinesque as Obliquaria interrupta. It is not, 

 therefore, preoccupied by Unio solenoides interrupta and, if 

 identifiable, would take precedence over Lea's name. 



Truncilla sulcata (Lea). 



Unio sulcatus Lea (1830) is not preoccupied by Pleurobema 

 mytiloides sulcata Raf. (1820). But Obliquaria obliquata Raf. , if 

 identifiable, would have priority. 



Plagiola securis (Lea). 



Obliquaria depressa Raf. (1820) is not preoccupied by the 

 Unio depressa Lam. (1819). But both Say (1834) and Conrad 

 (1834) have given preference to lineolata Raf. over depressa Raf., 

 although the latter has page precedence. This they had the 

 right to do under the Code and, if identifiable, Rafinesque's 

 name will take precedence over Lea's. 



Plagiola elegans (Lea). 



Truncilla truncata Raf. (1820) is not preoccupied by Unio 

 truncataSpeng]. (1793). If identifiable, Rafinesque's name has 

 priority over Lea's. MetaplataRaL is subsequent to both. 



Tritogonia tuberculata Bar. 



Unio tuberculata Bar. (1823) is not preoccupied by either 

 Obliquaria tuberculata Raf. or Obovaria striata tuberculata Raf. 

 (1820). But Obliquaria verrucosa Raf., if identifiable, has 

 priority for the species. 



