KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 50. N:0 5, 89 



CONTENTS. 



Page 



Introduction 3 



Systeinatical Section 5 



Geographical and Bathymetrical Distribution and General Observations 13 



TrimVt rtrcWca [(Solander) Humpheey 1797] 13 



N atica clausa Brod^rip & Sowerby 1829 14 



Natica bathybii Friele 1879 24 



Lunatia nitida (Donovan 1800) 24 



Lunatiacatena {T>x Costa 1778) 27 



Lunatia Montagui (Forbes 18.38) , 27 



Lunatia nana (Möller 1842) 30 



Lunatia 'pidlida (Bb.oi)'er.ip & Sowerby 1829) 31 



iMmaita<enMtsirirt<rt (Dautzenberg &FiscHER 1911 ) 40 



Amaurofsis islandica (Gmelin 1783) 44 



Acryhiajlava (Gould 1840) 46 



Lamellaria perspicua (Linné 1753) 47 



Lamellaria latens (MtJLLER 1776) 49 



General Remarks on the Genus Lamellaria 49 



Marseniella borealis Bergh 1886 51 



Marsenina glabra (Couthouy 1839) 51 



General Eemarks of the Genus Marsenina 52 



Velutina undata Beown 1838 55 



Velutina insculpta n. sp 59 



Velutina velutina (MiJller 1776) 60 



Velutina lanigera Miji.1,^11 1842 65 



Velutina pUcatilis (Muller 1876) 67 



General Remarks on the Genus Velutina 69 



Onchidiopsis glncialis (M. Sars 1851) 73 



Onchidiopsis groenlandica Bergh 1853 74 



Onchidiopsis hdissima n. sp 75 



General Eemarks on the Genus Onchidioijsis 76 



Description of the New Forms 81 



List of AVorks referred to 82 



Index 84 



Explanation of Plates 85 



Tryckt den 25 juli 1913. 



K. Sv. Vet. Akad. Handl. Band 50. N:o .5. 12 



