20 



UJVIO. 



442 Unio elongatus 

 442a sinuosus 



443 — — crassidens 

 444 Peruvianus 



445 purpuratiis 



446 ovatus (a) var. radiis longitudinalibus 



447 delodoii? 



448 Pictorum 



449 corrugatus^ two varieties 



450 luteolus 



451 marginalis 



452 Ovalis, Mont. 



453 



454 



455 



456 



457 



458 



459 



460 



HYRIA. 



461 Hyria avicularis 



462 corrugata 



463 elongata, Swains on 



AJVODON. 



464 Anodon sulcatus 



465 anatinus 



466 intermedius 



467 • trapezialis, a pair, one valve partly un- 



coated and polished 



468 rubens, one valve 



469 exoticus^ different stages of growth 



