. Bulletin of the British Museum (Natural History), Geology. 76 MORRIS, DICKINS AND ASTAFIEVA-URBAIT1S. Fig. 22 Wilkingia regularis (King, in de Verneuil). Lower Carboniferous, Visean (Asbian), Redesdale Ironstone, Redesdale, Northumberland. BM PL5002; Fig. 22a, left side, position of pallial sinus arrowed, periostracal pustules visible in postero-dorsal area, x2; Fig. 22b, right side with posterior adductor (PA), x2; Fig. 22c, oblique view of siphonal area of right side, showing posterior pedal retractor scar (PPR) and internal dorsal rib, approx. x3; Fig. 22d, umbonal area viewed obliquely f
. Bulletin of the British Museum (Natural History), Geology. 76 MORRIS, DICKINS AND ASTAFIEVA-URBAIT1S. Fig. 22 Wilkingia regularis (King, in de Verneuil). Lower Carboniferous, Visean (Asbian), Redesdale Ironstone, Redesdale, Northumberland. BM PL5002; Fig. 22a, left side, position of pallial sinus arrowed, periostracal pustules visible in postero-dorsal area, x2; Fig. 22b, right side with posterior adductor (PA), x2; Fig. 22c, oblique view of siphonal area of right side, showing posterior pedal retractor scar (PPR) and internal dorsal rib, approx. x3; Fig. 22d, umbonal area viewed obliquely from top, showing scars of anterior pedal retractor (APR) and accessory umbonal scars (US), approx. x4. low internal rib, running at a very low angle from the umbo towards the posterior margin. Remarks. Hind included Posidonomya transversa Portlock (1843: 174; pi. 38, fig. 9) in the synonymy of this species without comment. There is no indication from Portlock's figure that it belongs to this superfamily and we consider that Hind made a mistake. Another early nominal species that belongs in Wilkingia, Lutraria primaeva Portlock (1843: 441; pi. 34. fig. 5), was curiously interpreted by Hind (1900: 307) as an Edmondia. Hind went so far as to claim that another specimen had been substituted for the original, but it is clear that this is not so, from both Portlock's drawing and from his measurements. However, the measurements and the figure suggest that this species falls outside the variation of W. regularis, and it is probably a senior synonym of Allorisma monensis Hind. Wilkingia regularis differs from W. primaeva in being more elongate and having a differently shaped pallial sinus. Hind (1900: 424; pi. 48, figs 1-2) described specimens of this species from Lowick and Calderwood as Allorisma variabilis (M'Coy). The lectotype of that nominal species (Fig. 17, p. 69) is, however, a crushed specimen of Cosmomya, also from Lowick. Amongst Hind's specimens, the ribbing on the umbonal
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