. Bulletin of the British Museum (Natural History). FARINGDON SPONGE GRAVEL BRYOZOA 75 1899 Proboscina crassa (Roemer) var. divaricata d'Orbigny; Gregory: 35; pi. 2, fig. 8. Material. BM(NH) 60538, Cunnington Colin (figd as Proboscina crassa (Roemer) var. divaricata (d'Orbigny) by Gregory, 1899: pi. 2, fig. 8); D5150 (2 specimens), D5151, Cunnington Colin; D6325, A. N. Davies Colin; D7982-3, Treacher Colin; D55319, Little Coxwell Pit, Gaster Colin; D55320, Bowler's Pit, Gaster Colin (questionably assigned to this species); D55412, Little Coxwell Pit, Taylor Colin. Description. Zoariu
. Bulletin of the British Museum (Natural History). FARINGDON SPONGE GRAVEL BRYOZOA 75 1899 Proboscina crassa (Roemer) var. divaricata d'Orbigny; Gregory: 35; pi. 2, fig. 8. Material. BM(NH) 60538, Cunnington Colin (figd as Proboscina crassa (Roemer) var. divaricata (d'Orbigny) by Gregory, 1899: pi. 2, fig. 8); D5150 (2 specimens), D5151, Cunnington Colin; D6325, A. N. Davies Colin; D7982-3, Treacher Colin; D55319, Little Coxwell Pit, Gaster Colin; D55320, Bowler's Pit, Gaster Colin (questionably assigned to this species); D55412, Little Coxwell Pit, Taylor Colin. Description. Zoarium adnate, with narrow multiserial, ribbon-like branches, generally 2-3 autozooecia in width, bifurcating irregularly and, less commonly, giving rise to lateral branches at right angles. Branches are low and flat, sometimes anastomosing, with a gently tapering selvedge of narrow kenozooecia (visible in wetted specimens). Autozooecia are elongate, with small circular apertures a variable but large distance apart, and usually have short peristomes, though peristomes up to 0-3 mm have been observed; frontal walls are ornamented by rounded diamond- shaped pseudopores, about 1000 per mm". Measurements. TAM, 0-10-0-14 mm (mean 0-12 mm); TPM, 0-2(M)-24 mm (mean 0-23 mm); FWL, 0-90-1-20 mm; FWW, mean 0-30 mm; BW, 0-50-1 00 mm. Remarks. The Faringdon material agrees well with d'Orbigny's original description of P. marginata from the Aptian of Les Croutes (Aube), which emphasizes the presence of marginal kenozooecia ('cellules bordees'). Although d'Orb- igny (1853) found an ancestrula from Les Croutes, ancest- rulae have not been observed in Faringdon specimens, with the exception of a small colony (BM(NH) D55320) tenta- tively assigned to P. marginata but not developing the. Fig. 17 Drawing of part c>f a branch of Prohoscinopora tnari^inata (d'Orb-igny) in specimen BM(NH) D7982 showing the medial autozooecia and marginal keno/ooecia whose outlines are visible wlien the specimen i
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