Catat^ocui; Recunti^y DjsscribEd Mollusca 175 



be changed. Pending further consideration and final decision of the ques- 

 tions involved, it would be better to allow the accepted identification of 

 crassidens to stand. 



Unio gibbosus Barnes. 



Unio propeverutus De Gregorio, Moll, di aq. dul. di Amer., 1914, p. 8, pi. 3, 

 figs. la-c. 

 This species has been referred to Unio dilatata Raf. by Conrad and oth- 

 ers. Vanatta states (140, p. 355) that both U. dilatata Raf. and Ohliquaria 

 siniiata Raf. as represented in the Poulson collection are this species. If 

 identifiable from the original descriptions, both of Rafinesque's names have 

 priority. Dilatata has page priority in his Monograph. 



Unio pusii^IvUS Lea. 



Lea's name is not preoccupied in Unio by Obliquaria pusilla Raf. (1820) 

 as stated by Vanatta (140, p. 555) and will stand. 



Unio rafinivSouEi Vanatta. 



Unio ftiscatiis Lea, Simpson, Desc. Cat., 1914, p. 643. 



Vanatta has shown (140, p. 559) that fuscata was twice used by Raf- 

 inesque as varietal names for species of Unio and has proposed the name 

 given above for Lea's species. 



Unio tuomsyi Lea. 



Unio arctior fisheropsis De Gregorio, Moll, di aq. dul. di Amer., 1914, p. 15, 

 pl- 5, figs. 3a-c. 



Genus LASTENA Rafinesque, 1820. 



From an examination of the soft anatomy, Ortmann has recently (81, 

 p. 106) shown that this group belongs in the Unionince and not in the Ano- 

 dontincE. 



Hemistena Raf. is a synonym according to Frierson, (42. p. 7). 



Lasti^na lata Raf. 



Unio dehiscens oriensopsis De Gregorio, Moll, di aq. dul. di Amer., 1914, 

 p. 39, pl. 7, figs. 2a-b. 



This variety ( ?) is made the type of a new genus or subgenus, Saynnio, 

 the author does not seem to know which it should be considered. 



Genus GONIDEA Conrad. 1857. 



Ortmann has recently found from an examination of the soft anatomy 

 (83, p. 50) that this genus belongs to the Unionince. 



