Vol. I. M. S. Chang : — Brachiojjoda from the Orthis Bed (iii) 7 



of the Neichia Formation 



the Llandeilo of Great Britain and the latter with the Ortlioceras Umestone of 

 Sweden and the Vaginoceras hmestone of the Baltic Province of Russia. 



From the above lists of fossils it seems evident that in the Gorge District, 

 Yangtzeella poloi is the dominant fossil in the lower shale, but at Taihungshan, 

 Nanchang Hsien its place is taken by Orthis and others. In spite of careful search 

 Mr. Yii failed to discover a single specimen of Yangtzeella. The name "Triplecia 

 or Yangtzeella Beds" is then not apphcable in this case and the new term "Orthis 

 Bed" is, therefore, introduced. 



Most of the specimens in this lot are impressions of the interior or the ex- 

 terior part of the shell. In order to reproduce the true nature of the fossils the 

 making of molds is necessary. Unless otherwise stated, the following descriptions 

 are based on the characters of the molds, rather than on those of the specimens 

 themselves. 



DESCRIPTION OF SPECIES 



Genus LiNGULA Bruguiere 



1. Lingula sp. 



PI. I, Fig. la & b. 



This species is represented by a jjedicle valve, the anterior portion of which 

 has been broken off. It is oval or ovate in outline, with the broadest part across 

 or below the middle. The beak is not shown, though the posterior region suggests 

 slight tapering. The valve is moderately and evenly convex. The surface is 

 so weathered that it does not show any concentric lines of growth or markings 

 of any other kind. 



Remarks: The state of preservation of this species renders a precise deter- 

 mination impossible. 



Horizon and Locality: From the Orthis bed of the Neichiashan Forma- 

 tion, Taihungshan, Nanchang Hsien, Flupeh. Coll. C. C. Yu (Ser. No. X 249; Cat. 

 No. 3363). 



Genus OrTHIS Dalman 

 2. Orthis Calligramma Dalman, \ar. sinensis Chang (var. nov.) 



PL I, Fig. 2a & b. 



cf. 1869. Orthis calUgraimna Dalman. Davidson, British Fossil Brachiopoda, Pt. VII, No. Ill, p. 240, 

 pi. XXXV, figs. 1-17, varieties, figs. 18-24, (with Uteraturc references). 



This species is represented by one internal mold of the pedicle valve. It is 

 subquadrate to subsemicircular, wider than high and broadest at the hinge line. 



