Victorian Foi^sils, Part XII. VA\ 



of the j)edicle channel points to Liiu/ulella as the pi'obable 

 genus. The surface ornamentation is in parts well preserved, 

 and consists of strong concentric growth lines, crossed by fainter 

 radial lines, after the manner of Lingulella davisii, McCoy, ^ of 

 the Lingula Series of Great Britain, which species it also re- 

 sembles in outline but not in size, being much smaller. A species 

 of Li)ign,hUa, which Kayser compares with L. nathomti Lin- 

 arsson, has been figured by the former author2 from the Cam- 

 brian of the Liau-Tung Peninsula (China). It resembles our 

 specimen in shape, but does not possess any radial striae, such 

 as are clearly seen in our example. 



Dim ens I aim. — Length, 3.4 mm. ; width, 2.75 mm. 



Occurrence. — A single valve adhering to the glabella of 

 Ptyclioparia thielei. 



Horizon. — Upper Cambrian. Agnostus Zone. Dolodrook 

 River. 



Genus Orthis, Dalman, 1827. 

 Sub-genus Plectorthis, Hall and Clarke, 1892. 



Orthis (Plectorthis) platystrophioides, sp. nov. 



(PI. LTX., Figs. 14, 15). 



Description. — Shell of medium size, transversely oval ; 

 strongly costate. Hinge-line as long as the entire breadth of 

 the shell ; cardinal extremities produced or ending in an acute 

 angle. Dorsal valve semicircular, transversely elongate, moder- 

 ately and evenly convex, with a faint sinus bearing two costae. 

 Pedicle valve deeper, strongly convex on the median fold, and 

 depressed towards the cardinal angles. Beak prominent and 

 incurved. Area moderately wide, triangiilar ; delthyria large, 

 open ; dorsal or brachial valve with a conspicuous cardinal pro- 

 cess. Surface of valves with 16-20 strong plicae, with an occa- 

 sional finer riblet interposed between the primary ones. Faint 

 indications of concentric growth-lines or transverse plicae, with 

 one or two strongly emphasised growth-stages. 



1 McCoy. Brit. Pal. Foss., 1852, p. 252, pi. i.-l., %. 7. 



2 In Kichthofeti's "China," vol. iv., p. 35, pi. iii., fig. 3. 



