Scientia Sinica

No. 1 WANG: NEW SPECIES OF BRACHIOPODS [1] 167

Discussion: This species is represented by a sirigle complete specimen which was collected from the same bed with Yangtzeella polo: and Martellia ichangensis (sp. nov.). Because of the scarcity of material, the details of the interior of this species are impossible to be ascertained. The surface ornamentation of this species resembles Porambonites more than Hemzpronites. But in regard to the characters of the rotund form, the strongly biconvex lateral profile and the rectimarginate anterior commissure, the present specimen is Hemipronitoid. Inside the dorsal valve, the brachiophore supporting plates are widely divergent and short, unlike Porambonites, of which the brachiophore lamellae are subparallel and extend forward about to the middle of the valve. The generic assignment of the present specimen is tentative.

Genus Paleostrophia Ulrich and Cooper 1936 Paleostrophia recta Wang (sp. nov.) (Pl. Il, A; Figs. 1-3)

Shell small; subrectangular in outline; lateral profile subequally biconvex, dorsal valve having greater convexity; hinge-line straight, about equal to the width of the shell; cardinal extremities obtusely angular; anterior commissure strongly uniplicate. Surface smooth, only ornamented by few concentric lines.

Ventral valve gently convex, highest in the umbonal region; lateral margins sharply subangular; sulcus deep and wide, originating from the beak; beak minute.

Dorsal valve strongly convex, greatest convexity anterior to the middle of the valve; fold highly elevated, short, rounded, widening anteriorly and originating a little behind the middle of the valve; lateral flanks broadly convex, giving the shell a trilobate appearance in anterior view.

Syntypes, LP.A.S. 8005, 8006, 8007.

Horizon and locality: Upper Cambrian; a small hill behind Tsingshan- tsun Village, west of Chiawang Colliery, Kiangsu Province.

Collector: J. C. Sheng.

Discussion: All specimens of this species available for study are crowded in a slab of white limestone with the shells badly exfoliated. This species is characterized by the rectangular general contour, the wide hinge-line and the high, rounded fold confined to the anterior half of the shell. These features and its small size serve to differentiate it from Paleostrophia orthia (Walcott)", a well-known species from the Upper Cambrian limestone of Shantung Province.

Genus Pentamerus Sowerby 1813 Pentamerus dorsoplanus Wang (sp. nov.) (Pl. Ill, B; Figs. 15; Pl. IV, B; Figs. 1-3)

1911, P. borealis, Fresh: von Richthofen’s China, Vol. 5, p. 15, pl. 4, fig. 3.