Synagoga arabesque sp. nov., female. General morphology, inner structures of carapace and mantle (SEM) A general view ventral B right valve of carapace, inner surface, mantle at place of body attachment (entrance of gut diverticulum and adductor muscle) destroyed C enlarged detail of mantle surface near anterior margin, submarginal fold of mantle with cuticular fringe (indicated by arrowheads) D frontal filament complex, anterior end left E Entrance of anterior pit of carapace (indicated by arrowheads) F surface of anterior pit of carapace (cuticular papillae indicated by asterisks). Abbreviations: a1 – antennules, ab – abdomen, ar – anterior ramus of frontal filament complex, bs – basal ramus of frontal filament complex, ca – carapace (valve), ffc – frontal filament complex, fr – furcal ramus, pr – posterior ramus of frontal filament complex, te – telson, th – thorax, thp1-6 – thoracopods I–VI. Scale bars: in μm.