Substrate: coral rock; Sampled and identified by C. Schönberg. All measurements are of mature, fully formed endosomal oxeas to allow statistical comparison with other samples. Measurements conducted by C. Schönberg on preparation of acid-cleaned spicules made by C. Schönberg. Data are sorted vertically by spicule width.; Schönberg, Christine H. L.; Tapanila, Leif (2006) The bioeroding sponge Aka paratypica, a modern tracemaking analogue for the Palaeozoic ichnogenus Entobia devonica. Ichnos 13: 147-157 (QM G322242: pp. 148-150 and 153, Fig. 4, Tab. 2).