Review of the Tertiary and Recent Neozelanic Pyramidellid Molluscs. No. 4—The Syrnolid Genera. By C. R. Laws, D.Sc., Auckland. [Read before the Auckland Institute, July 19, 1937; received by Editor, July 22, 1937; issued separately, December, 1937.] True Syrnolids are typically considerably elevated, often very attenuate, and imperforate, with a single more or less strong plait on the columella, and a strongly exsert, Turbonilla-like larval shell. Axial sculpture is usually not present, but in Costosyrnola n.gen. axial ribs are developed, though they become obsolete early on the posterior part of the whorls. Microscopic spiral striae may, or may not, be developed. Costosyrnola n.gen. is exclusively fossil, and is not represented after Lower Miocene times. Finlayola n.gen. is found in the Lower Miocene, after which it does not appear as a fossil; but it reappears in the Recent fauna as a single species with a somewhat different style of shell, though of similar embryonic character. Syrnola A. Adams has persisted right down to the present from the time of its first appearance in beds of mid-Oligocene age. Tibersyrnola n.gen. is a fossil group known so far in only Awamoan and Castle-cliffian faunas. Puposyrnola Cossmann has an undoubted ancestor in the Upper Oligocene, and is not again found until it appears in the Recent fauna (2 species). Key to Syrnolid Genera. Key to Syrnolid Genera. Axial ribs absent. Lirations present within outer lip. Apex helicoid with small, central, lateral nucleus. Tibersyrnola. Lirations not present within outer lip. Outline of distinct pupoid aspect. Whorls flattish, aperture ovate-rotund, its rim heavy and a thick pad of callus on inner lip; immersion of embryo reminiscent of that of Odostomia. Puposyrnola. Outline not of pupoid aspect. Protoconch helicoid with small, central, lateral nucleus. Syrnola. Protoconch of one volution, lateral nucleus large and excentric; not helicoid. Finlayola. Axial ribs present. Protoconch helicoid with small, central, lateral nucleus. Costosyrnola.