1870.] 245 [Ball. 



Subclass EXOCEPHALA. 

 Order Rhiphidoglossa Trosch. 



Suborder Scutibranchiata Gray. 



Adeorbis S. Wood. 



liotiid^e Gray. Margarita Leach. 



M. cinerea, p. 279. M. minu- 



tissima and M. undulata, p. 

 A. costulata, p. 278. m M ^.^ p ^ 



trochid^ Gray. M ' ^mpanulata and M. ar- 



gentata, p. 282. M. obscura, 

 Calliostoma Swains. p. 283. M. acuminata, p. 



C. occidentals, p. 286. 284. M. varicosa, p. 285. 



Suborder Dlcranobranchiata Gray. 



FISSURELLID.E. 



Cemoria Leach. C. noachina, p. 276. 



Order Docoglossa Trosch. 



Suborder Cervicobranchiata Gray. 

 tecturid^e Gray. 

 Tectura Aud. T. testudinalis, p. 267. T. alveus, p. 269. 



Suborder Abranchiata GilL 

 lepetid^: Dall ex Gray. 

 Lepeta Gray. L. coeca, p. 270. 



Order Polyplacophora Gray. 



chitonid^e Gray. reus, p. 26 L T? mendica- 



LeptOCllitOll Gray. rius, p. 263. T ? apiculatus, 



L. cinereus, p. 259. L?albus, p. 258. 



p. 263. Auricula Gray. 



Tonicia Gray. A - Emersonii, p. 264. 



T. ruber, p. 260. T. marmo- 



