. Bulletin of the British Museum (Natural History), Geology. 182 SMITH two forms, it is impossible to tell to which species either belongs. His assignment of one to C. inflatus is therefore accepted tentatively. C. inflatus differs from C. cf. baluchistanensis (Noetling), the other species described here, on several counts. Firstly, it has finer tuberculation on its oral surface at comparable sizes. Secondly, its peristome is proportionally smaller at compa- rable sizes, and thirdly, its periproct is smaller and more removed from the ambitus at all sizes (Fig. 42). There is a stratigraphi
. Bulletin of the British Museum (Natural History), Geology. 182 SMITH two forms, it is impossible to tell to which species either belongs. His assignment of one to C. inflatus is therefore accepted tentatively. C. inflatus differs from C. cf. baluchistanensis (Noetling), the other species described here, on several counts. Firstly, it has finer tuberculation on its oral surface at comparable sizes. Secondly, its peristome is proportionally smaller at compa- rable sizes, and thirdly, its periproct is smaller and more removed from the ambitus at all sizes (Fig. 42). There is a stratigraphical variation in profile. The taller forms, exactly comparable in form with the Iranian type, are found lower down in the sections in the coarse calcarenites: in bed 2 at Jebel Rawdah section 4, In bed 6 at section 2, and in bed 13 at section 4. The more depressed forms are found higher up in the more orbitoline-rich limestones and may represent deeper water morphological varieties. Coenholectypus cf. baluchistanensis (Noetling, 1897) PI. 18, figs 1-6; Figs 42, 43B, D cf. 1897 Holectypus baluchistanensis Noetling: 18, pi. 3, fig. 3. Material. Thirteen specimens (BMNH EE3386-98). Occurrence. In the western Oman mountains this species was found at the following localities and horizons: Jebel Buhays, section 1: loose in scree (3) and bed 8 (1). Jebel Thanais, lowest 2 m of limestone section (1). Jebel Rawdah, section 1: 20 cm below the top of bed 5 (1). Jebel Rawdah, section 2: bed 11 (9). It was originally described from the Maastrichtian of Bal- uchistan. Description. Tests are circular in outline and range from 18-37 mm in diameter. They are moderately inflated in profile (PI. 18, fig. 3), with a test height 55-62% of test length. The ambitus is rounded and lies a little below mid-height. The apical disc has five gonopores. The four genital plates are small and pentagonal and separated from each other by ocular plates that are similar in size (Fig. 43D). The madreporite plate i
Size: 2283px × 1095px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorbritishmuseumnaturalhistory, bookcentury1900, bookcoll
