Koefoed 1960. Isospondyli 2, Heterophotodermi 2, from the "Michael Sars" North Atlantic deep-sea expedition 1910 (with addenda et corrigenda to Isospondyli 1 and 2:1). Report of the Scientific Results ' Michael Sars ' N Atlant Deep-sea Exped 1910, 4 Pt. 2(No. 8) 1960: 1-15