The Javan fossil corals collected by the Austrian frigate Novara included a specimen on which Reuss (1866, p. 172) founded a new genus, Polysolenia. He described it (ibid., p. 172) as showing in the structure of its cœnenchyma “eine überraschende Ähnlichkeit mit Polytremacis und Heliopora”. “Das Cönenchym besteht aus langen, ziemlich dicken, geraden, neben einander liegenden Röhren.” These tubes, according to his account, occur in circles of six around a central tube. Reuss repeated (p. 174) that the cœnenchyma is composed of regular parallel tubes (Röhren), whereby it is closely allied to Heliopora and Polytremacis. He named it Polysolenia “nach ihrer röhrigen Structur”. Reuss' illustrations suggested some suspicion as to the accuracy of his description, since the dark parts of his figures might be interpreted as the original solid structures of the coral, and the light parts as the matrix. If so, the cœnenchyma would be trabecular and the septa a series of thin lamella. Reuss, however, was emphatic that the septa are thicker than the walls of the supposed cœnenchymal canals; and, if so, the light parts of the figure represent the original solid structures. If the coral had undergone a double change in fossilization Reuss' view was possible; and his statements that the circular rods are casts of canals were so positive that, though in 1900 I mentioned my doubts, I felt bound to dismiss them. So I accepted the fossil as a Miocene Helioporid, and as the name Polysolenia was preoccupied renamed the genus Octotremacis (1900, p. 302).