X CONTENTS. 



Systematic arrangement — Continuetl. 

 Gastropoda— Continued. 



Order Ctenobrancbiata — Continued. Page. 



Family Cerithiidae 8S 



Genus Bittium 88 



priscum 88 



(priseum vai\V) sora 80 



adela SO 



Genus Ceritliium 89 



georgianum '. 89 



praecursor 90 



up. indet 90 



plectrum 90 



Genus Potamides 91 



liillsboroensis 91 



(Lampanella) transecta 91 



(Pyrazisinus) campanulatus 92 



cornutus 92 



acutus 92 



Family Cerithiopsidae . 93 



Genus Ceritliiopsis 93 



silicata 93 



Family Trichotropidae 93 



Genus Trichotropis 93 



(Ceritliioderma) prima 93 



Family Modulidae 94 



Genus Modulus I 94 



turbinatus 94 



Family Littoi'inidae 94 



Genus Lacuna 94 



precursor 94 



Family Caecidae 95 



Genus Caecum 95 



solitarium 95 



Family Vermetidae 95 



Genus Serpulorbis 95 



granifera 95 



ballistae ' 05 



decussata 96 



Genus Petaloconclms 90 



varians 96 



Genus Vermicularia 96 



(Anguiuella) virgiuica 96 



Genus Siliqnaria 97 



vitis 97 



Family Turritellidae 97 



Genus Turritella 97 



tampae 97 



var. tripartita 97 



(tampae var.?) medioconstricta 98 



imgodaeformis 98 



megalobasis 98 



chipolana 98 



