FAMILIES AND GENERA. 105 



TritonidSB. (PROSOBRANCHIATA.) Plate xxv. 

 Triton, 459, 460. 



Tritoniidse. (OPISTHOBRANCHIAIA.) Plate xxxii. 



Tritonia, 602. 



Truneatellidse. (PROSOBRANCHIATA.) Plate xxiii. 

 Truncatella, 399. 



TllPbinidse. (PROSOBRANCHIATA.) Plate xxii. 

 Phasianella, 355. 



TurritellidSB. (PROSOBRANCHIATA.) Plate xxv. 

 Tiwritella, 452. 



Unionidse. (EULAMELLIBRANCHIATA.) Plates vi., vii. 



Unio, hinge with teeth strongly marked, lunule distinct, shell 

 solid, 55-57. 



Anodonta, teeth rudimentary or absent, lunule indistinct, shell 

 thin, 58, 59. 



Valvatidse. (PROSOBRANCHIATA.) Plate xxiv. 

 Valvata, 441, 442. 



Veneridse. (EULAMELLIBRANCHIATA.) Plate ix. 



Circe, three cardinals in each valve, outer one in left valve on 

 posterior side cloven in two, 113. 



Venus, pallial sinus angular, 114-121. 

 Lucinopsis, two cardinals only in left valve, 122. 

 Tapes, pallial sinus rounded, 123-126. 

 Venerupis, shell oblong with concentric plates, 127. 



Viviparidse. (PROSOBRANCHIATA.) Plate xxv. 

 Viviparus, 439, 440. 



