172 BIOLOGICAL SURVEY OF 



GASTEROPODA 



Subclass STREPTONEURA 



ASPIDOBRANCHIA 



Acmaeidae 

 AcMAEA Eschscholtz 



ACMAEA TESTUDINALIS (MuUer) 



AcMAEA ALVEUS (Conrad) 



Lepetidae 

 Lepeta Gray 

 Lepeta caeca (Miiller) 



Fissiirellidae 

 Puncturella R. T. Lowe 

 PuNCTURELLA PRiNCEPS (Mighels and Adams) 



Trochidae 

 Margarites Leach 

 Margarites cinerea (Couthouy) 

 Margarites groenlandica (Gmelin) 

 Margarites helicina (Phipps) 

 Margarites olwacea (Brown) 



Molleria Jeffreys 

 Molleria costulata (Moller) 



Solariella S. Wood 



SOLARIELLA OBSCURA (Couthoiiy) 



Calliostoma Swainson 

 Calliostoma occidentale (Mighels and Adams) 



CTENOBRANCHIATA 

 Pyramidellidae 



TURBONILLA RisSO 



TuRBONiLLA NivEA (Stimpson) 



