VI 



THK NAUTILUS 



Unionidse of Eastern Texas, Critical notes on . . . 74 



Unio radiatus and Unio luleolus, Distinguishing characters 



of 77, 112 



Unionidae, Notes on ....... 86 



Unio Oscari, n. sp. Florida. . . . . . . 124 



Vaginulus Schivelya. (PI. II, figs. 6, 7, 8) . . . 39 



Vallonia, Notes on North American forms of . . . 100 

 Vivipara, New variety of .... .142 



Zonites Shimekii. (PI. II, figs. 9, 10, 11) . . 39 



Zonites Brittsii, n. sp. .... . 99 



