Silurian and Devonian brachiopods from Severnaya Zemlya (Russian Arctic) Author Modzalevskaya, Tatiana L. All-Russia Geological Research Institute (VSEGEI), Srednij pr. 74, St. Petersburg, 199106 (Russia) modz @ IB 2567. spb. edu. text Geodiversitas 2003 25 1 73 107 journal article 10.5281/zenodo.5375016 1638-9395 5375016 Pentlandina ? sp. ( Fig. 4 ) MATERIAL EXAMINED. — A single shell, embedded in rock matrix, from loc. 29a, Lednikovaya River, October Revolution Island ( Männik et al . 2002 : fig. 1); Vodopad Formation. REMARKS A single small shell (L = 6.7 mm , W = 1.1 mm ) with biconvex profile, semielliptical outline, deep ventral sinus, and prominent dorsal sulcus is attributed to Pentlandina ? sp. The hinge line is shorter than the maximum width. The ventral interarea has a large delthyrium, closed by pseudodeltidium. A small chilidium is filled by a bilobate cardinal process. Ornament is parvicostellate with new ribs intercalating. Shells of Pentlandina from the middle Llandovery of West Shropshire have the same size and shape ( Cocks 1968: 293 , pl. I, fig. 13). However, the specimens from Severnaya Zemlya lack any sign of the ventral muscle field well visible on the shells from Shropshire. FIG. 5. — Brachyprion ruminatus n. sp. ; A , B , pedicle valve (holotype N 9/12991), loc. 11, bed 14A, Samojlovich Formation; A , ventral view; B , lateral view; C , ventral view of an internal mould of a pedicle valve (N 10/12991), loc. 11, bed 14, Samojlovich Formation; D , ventral view of an internal mould of a pedicle valve with well developed impressions of concentric rugae (N 11/12991); E , note the radially arranged pseudopunctae at anterior margin (N 12/12991), loc. 11, bed 20, Samojlovich Formation. Scale bars: A, B, D, 6 mm; C, 5 mm; E, 2 mm. Family STROPHEODONTIDAE Caster, 1939