II 



INDEX. 



Helix peripberia 49 



riparia 49 



? veterna 48 



1 vetusta 48 



(Zonites) marginicola 47 



Hyalina? evansi 46 



occidentalis 64 



Hydrob.ia antlionyi 59 



1 enliraoides 59 



recta 60 



subconica 59 



utabensis 60 



warrenana ,... 59 



Introductory remarks 5 



Latia dallii 45 



Lea, Dr. Isaac, description of fossil Uniones 72 



Linmsea (Acella) baldemani 39 



? compactilis 39 



(Limnopbysa) nitidula 39 



meekii 40 



minuscula 40 



(Polyrhytis) kingii 40 



sbumardi 40 



similis 39 



vetusta 39 



Limnieidai 38 



Lioplacodes veternus 60 



List of species 66 



Lithasia antiqua ' 59 



Macrocy clis spatiosa 46 



Margaritana nebrascensis 21 



Melampus ? antiquus 38 



Melania claibornensis 54 



decursa 73 



inscalpta 54 



sculptilis 55 



subsculptilis 55 



taylori 55 



wyomingensis 54 



Melaniidaj 53 



Melanopsis americana 55 



Micropyrgus minutulus 59 



Morton, Dr. S. G., description of fossil 



Uniones 72 



Mytilidre < 17 



Naiadites carbonaria 19 



elongata ' 19 



laevis 19 



Neritida* 51 



Neritina bannisteri 52 



bruneri 53 



naticiformis 52 



nebrascensis 51 



(Velatella) baptista 52 



bellatula 52 



carditoides 52 



volvilineata 52 



Ostrea glabra 15 



subtrigonalis 15 



Ostreidse 14 



Pby sa biidgerensis 44 



carletoni 43 



copei 44 



felix ' 44 I 



Page. 



Pliyaa pleromatis 44 



secalina 44 



Physidee 43 



Pisidium saginatum 34 



Pisidiidse 34 



Planorbis asqualis 42 



(Batbyomphalus) amplexus 41 



kanabensis 41 



planoconvexus. 41 



eirratus 42 



convolutus 41 



(G-yrauIus) militaris 41 



leidyi 42 



lunata 42 



nebrascensis 42 



utabensis 41 



var. spectabilis 41 



veternus 40 



vetustus -.- 42 



(Plenrolinmaea) tenuicostata 39 



Pupa arenula 50 



atavuncula 50 



bigsbyi '. 50 



incolata 50 



vermillion en sis 50 



vetusta 50 



Pupidie 49 



Prygulifera humerosa 54 



Rhy topliorus meekii 38 



priscus 38 



Rissoidse 59 



Sphperium formosum 33 



idahoense 34 



planum 33 



recticardinale 33 



rugosum 34 



subellipticum 33 



Stropbites grandseva 49 



Succinea (Brachyspira) papillispira 51 



Succinidje 51 



Spurious and doubtful species 72 



Tbaumastuslimnanformis 48 



Tiilotoma tbompsoni 61 



"Unio clavus 25 



aldricbi 27 



belliplicatus 24 



bracby opisthus 27 



clinopistbus 28 



couesii 26 



cristonensis 19 



cryptorbyncbus 25 



deweyanus 25 



endlicbi 26 



goniambonatus 27 



goinonotus 27 



haydeni 29 



bolmesianus 27 



bubbardi 21 



mendax 27 



nucalis 20 



peuultimus m 21 



primaivus 26 



priscus 26 



proavitus 27 



