The Syllinae and Eusyllinae were studied in two similar habitats in the Gulf of Elat and on the Mediterranean coast of Israel. These were porous reefs of vermetid (
Dendropoma spp.) tubes encrusted on seaward margins of intertidal platforms. In the Mediterranean habitat there were 11 species: nine Syllinae and two Eusyllinae. Four species are new records for the Israeli Mediterranean coast. Twenty-five species were identified from the Gulf of Elat habitat: 20 Syllinae, five Eusyllinae. Twenty-three were new records; three additional species (two Syllinae, one Eusyllinae) not fully identified, are also presumed to be new records. One new subspecies,
Syllis truncata mediterranea, is described from the Mediterranean habitat; two new species,
Syllis lunaroides and
S. safrieli and five new subspecies,
Syllis lunaris minima,
S. alternata kabilica,
S. truncata cryptica,
Langerhansia rosea curticirris, and
Pionosyllis lamelligera pariseta are described from the Gulf of Elat habitat.