CLASSIFICATION xiii 
PAGE 
Superfamily STREPTODONTA 
BatiilyoSCALIDAR: osjnciye: «22 ve caea ses oe 
Superfamily GYMNOGLOSSA 
Family EULIMIDALE...............+-+-- 13 
Family PYRAMIDELLIDAE............. 18 
Superfamily TAENIOGLOSSA 
Family CASSIDIDAE..............---+: 14 
Family DOLIIDAE.............--..:+++. 14 
Family AMPHIPERASIDAE............ 14 
Family CYPRAEIDAE..............---- 14 
Family STROMBIDAE...............--- 15 
Family TRIRORTDAB 2.002 25 sconce le 
Family CERITHIOPSIDAE............. 15 
Family CERITHIIDAE..............--:- 15 
Family VERMETIDAE ..............--- 15 
Family CAECIDAE.........:.....:.---: 15 
Family LITORINIDAE............--.--- 15 
Family PAGIOPIDAE. ...2..5-25-..002-+5 19 
RamilysRISSORDAES 2j22 00525: 5-40--- 15 
Family ASSIMINEIDAE.............-..- 16 
Family AMNICOLIDAE................. 16 
Family VIVIPARIDAE................-.- 16 
Family PLEUROCERIDAE.............. 16 
Family CALYPTRAEIDAE............-. 17 
Family NATICIDAB.. .ycosedls-.2s 0 17 
Superfamily RHIPIDOGLOSSA 
Family TROCHIDAE.....) 02. -<+-5-- 17 
Family TIOTIIDAL. «02225522 caeeecss 18 
Family CYCLOSTREMATIDAE......... 18 
Superfamily ZYGOBRANCHIA 
Family FISSURELLIDAE.............-. 18 
Subclass ISOPLEURA 
Order POLYPLACOPHORA 
Superfamily MESOPLACOPHORA 
Family ISCHNOCHITONIDAE......... 19 
