Genus Branneroceras PLUMMER et SCOTT, 1937 T y p e s p e c i e s. Gastrioceras branneri SMITH, 1896; by original designation. D i a g n o s i s. Genus of the family Schistoceratidae with subdiscoidal, evolute conch with moderate to wide umbilicus. Ornamented with prominent ribs on or adjacent to the umbilical shoulder. In widely umbilicate forms the ribs are long and more strongly developed than in the narrowly umbilicate forms; these ribs decrease in size and robustness until they become more like nodes. Ventral region ornamented by prominent sinuous transverse lirae with wider interspaces, forming rounded prominent ventral and lateral sinuses and corresponding salients between, crossed by finer longitudinal lirae, giving a cancellate...