中文摘要：

新材料表明定远虫（Tingyuania）和双岛虫（Dinesus）这两个三叶虫属是有效的,前者并不是后者的晚出异名。双岛虫类的地质延限被下延至传统早寒武世晚期的清虚洞组。补充描述首次发现的定远虫的尾部,并描述双岛虫的一新种。

英文摘要：

New materials show that the Cambrian trilobite Tingyuania Sun et Chang in Chang 1937 is a valid genus, rather than a junior synonym of Dinesus Etheridge, 1896. Specimens assigned to Ting- yuania typica Sun et Chang, 1937, including a pygidium that is the first recorded pygidium for the genus Tingyuania, collected from Laoyingshan Section, Huainan, Anhui Province, are illustrated herein. A new species of Dinesus, D. panxinicus sp. nov., is described from traditionally upper Lower Cambrian Tsingshiutung Formation at Panxin, Guizhou Province. DESCRIPTION OF NEW SPECIES Genus Dinesus Etheridge, 1896 Type species Dinesus ida Etheridge, 1896 Dinesus panxinicus sp. nov. （PlateI ,figs. 5-12） Holotype NIGPAS151302, plate I , fig. 12. Paratypes NIGPAS151298-151301, plate Ⅰ , figs. 5-11. Etymology After the locality name, Panxin town, Songtao, Guizhou. Diagnosis A species of Dinesus with long stout occipital spine and intergenal spine on the margin of posterior border. Description Glabella convex, cylindrical in outline, rounded anteriorly. S1 deeply incised, slanting backward and inward onto occipital furrow, isolating a suboval L1 from glabella. Axial and occipital furrows wide and deep. Occipital ring wide, narrowing distally and projecting rearward a long occipital spine from posterior margin. Anterior border convex, arching forward slightly. Preocular field bearing a shallow furrow extending forward and outward from the anterior corner of gla- bella at angle 45° to sagittal line. Preglabellar field concave sagittally, isolating a triangular lobe in inner portion of anteroior field. Palpebal lobe convex, medium in size, separating from fixigena by deep palpebral furrow, located at the mid-length of the glabella. Eye ridge weak, diagonally directed. Anterior branch of facial sutures slightly divergent; posterior branch directed backward and outward, enclosing a triangular posterolateral projection. Posteror border furrow deep and wide, posterior border widening laterally with an intergenal spine on posteri