FAMILIES AND GENERA. 



GastPOChcenidse. (EULAMELLIBRANCHIATA.) Plate xiv. 

 Gastrochcena, 159. 



(EuLAMELLiBRANtniATA.) Plate xiv. 



Saxicava, pallial scar interrupted or broken up into separate 

 spots, 156, 157. 



Panopaa, pallial scar entire, 158. 



GoniodOPidSB. (OPISTHOBRANCHIATA.) Plate xxxiii. 



Goniodoris, oral tentacles flattened and angular, 609. 



Ancula, oral tentacles of two tubercular processes on the sides of 

 the head, 6to. 



Idalia, no oral tentacles, 6n. 



Haliotidse. (PROSOBRANCHIATA.) Plate xxi. 

 Haliotis, 333. 



Helieidse. (PULMONATA.) Plates xix., xx. 



Vitrina, shell greenish, subglobular, thin, vitreous, no umbilicus, 

 247. 



Zonites, shell orbicular, thin, mouth oblique, umbilicus more or 

 less distinct, 248-258. 



Bullmns, shell long and spiral, mouth oval, umbilicus small, 

 259-262. 



Helix, shell globular or flattened, mouth circular or oval, outer 

 lip generally thick and having a rib, sometimes reflected and 

 toothed, 263-287. 



Hermseidse. (OPISTHOBRANCHIATA.) Plate xxxi. 

 Herman, tentacles 2, body ovate, 586. 

 Alderia, tentacles none or rudimentary, body tapering, 587. 



HomalOgyPidse. (PROSOBRANCHIATA.) Plate xxiii. 



Homalogyra, 385, 386. 



HydPObiidse. (PROSOBRANCHIATA.) Plate xxiv. 



Hydrobia, eyes on tubercles, operculum horny, 426-429. 

 Bithynia, eyes sessile, operculum shelly, 430, 431. 



lanthinidse. (PROSOBRANCHIATA.) Plate xxii. 

 lanthina, 357. 



Jeffpeysiidse. (PROSOBRANCHIATA.) Plate xxiv. 

 Je/reysia, 435-437- 



LamellaPiidse. (PROSOBRANCHIATA.) Plate xxiii. 



LameUavia, shell internal, ear-shaped, very thin, 377, 

 Vehitina, shell external, cap-shaped, spire small, suture deep, 

 37 8 . 379- 



