. Bulletin of the British Museum (Natural History). ARENIGTRILOBITES FROM BANGOR 11. Fig. 10 Asaphellus cf. graffi (Thoral). All material from Loc. A. a: Itl9822 (x2), poor internal mould of pygidium showing doublure, b: Itl9829 (x3), latex cast of external mould of broken hypostome. c: Itl9831 (x7-5), internal mould of hypostome. d: Itl9827 (x 1-25). latex cast of external mould of pygidium. e: It 19803 (x 118), latex cast of external mould of free cheek, f, i: It 19824 (x 1-25), latex cast of external mould of pygidium. g: It 19838 (x 1-25), internal mould of free cheek, h: Itl9833
. Bulletin of the British Museum (Natural History). ARENIGTRILOBITES FROM BANGOR 11. Fig. 10 Asaphellus cf. graffi (Thoral). All material from Loc. A. a: Itl9822 (x2), poor internal mould of pygidium showing doublure, b: Itl9829 (x3), latex cast of external mould of broken hypostome. c: Itl9831 (x7-5), internal mould of hypostome. d: Itl9827 (x 1-25). latex cast of external mould of pygidium. e: It 19803 (x 118), latex cast of external mould of free cheek, f, i: It 19824 (x 1-25), latex cast of external mould of pygidium. g: It 19838 (x 1-25), internal mould of free cheek, h: Itl9833 (x 1-25), latex cast of external mould of free cheek, j; It 19820 (x7-5), internal mould of hypostome. cranidium where it reaches one quarter of the maximum preocular width (tr.) of cranidium; it narrows towards the midUne. Though poorly preserved there is no evidence of any occipital furrow, and only slight evidence of a posterior border furrow. Free Cheek. Fxtcrnal margin gently curved and extending posteriorly into pronounced genal spine, which becomes broader and more truncate in larger specimens. Preocular and postocular sutures fairly straight for majority of length and strongly curved at their abocular ends. This curve turns the postocular suture through about MO", to rim perpendicular to the immediately adjacent part of gcnal spine, and thence to the posterior margin of cranidium. Preocular suture cur\'cs to become parallel with front margin of cranidium, with a thin extension of the dorsal exoskeleton continuing external curvature of the free cheek. The two sutures converge at an angle just less than 90° in plan view, and are of approximately equal length. In plan view a brt)ad concave border occupies just less than half the maximum width. Doublure is co-extensive and slightly more concave in profile. Terrace lines are faintiv developed on the doublure. A panderian opening is present on just interior to paradc>ublural line and close to posterior marg
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