. Bulletin of the British Museum (Natural History). FARINGDON SPONGE GRAVEL BRYOZOA 127. Fig. 136 Semimulticavea marginata (Canu & Bassler), BM(NH) D57722, thin section; 136A, vertical section through the origins of a stack of subcolonies, x 22; 136B, detail showing some zooecia continuing from parent to daughter subcolony, x 55; see also Fig. 135. common Faringdon species. Unfortunately, the holotype of S. marginata (Canu & Bassler) is heavily worn (Fig. 130) and does not show the ?pseudolunaria of the autozooecia. 5. marginata bears a close resemblance to Ceriopora (Reptono
. Bulletin of the British Museum (Natural History). FARINGDON SPONGE GRAVEL BRYOZOA 127. Fig. 136 Semimulticavea marginata (Canu & Bassler), BM(NH) D57722, thin section; 136A, vertical section through the origins of a stack of subcolonies, x 22; 136B, detail showing some zooecia continuing from parent to daughter subcolony, x 55; see also Fig. 135. common Faringdon species. Unfortunately, the holotype of S. marginata (Canu & Bassler) is heavily worn (Fig. 130) and does not show the ?pseudolunaria of the autozooecia. 5. marginata bears a close resemblance to Ceriopora (Reptonodicava) nodosa Keeping, 1883, the syntypes (SM B26133-9) of which have been studied. Keeping's specimens of this species from the Aptian of Upware share with S. marginata large multilamellar colonies composed of nume- rous subcolonies. However, the subcolonies are larger and the monticules typically higher than in S. marginata. Further- more, dimorphism of the zooecia is not clearly developed and pseudolunaria cannot be observed, though this may be be- cause of the abraded state of the material. Colonies of 5. marginata are distinctive on account of their multilayered structure and typically large size. Probably the carrot-shaped colonies of S. marginata came from a pit closed long ago; none have been found in the last fifty years (carrot- shaped colonies also occur in C. nodosa Keeping, SM specimens B26137 and B29139). Hemispherical colonies are also much less commonly found nowadays than they were in the past. Serpulid tubes are encountered embedded within colonies between successive layers. These worms evidently fouled the surfaces of living colonies and were subsequently trapped by the growth of new overarching subcolonies. Also commonly associated with S. marginata are boring bivalves whose crypts (ichnogenus Gastrochaenolites) are found penetrating many colonies (Fig. 129). Genus SEMIJSODICRESCJS d'Orbigny, 1854 Type species. Seminodiiresets nodosa d'Orbigny, 1854, b
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