(ill) 10 Palxontologia Sinica Ser. B. 



Davidson's Orthis carausil as represented in fig. 1, PI. XXXIII, gives the 

 following results: 



Greatest width = 18 mm 

 Hinge line = 16 mm 



Height = 11.5 mm 



Proportion of height to width = 1.57 



Remarks: This species resembles Orthis carausii in its form as shown in the 

 above measurements, but it difl^^ers in the following respects: (1) greatest width at 

 the hinge fine instead of a little below; (2) more numerous and complicated plica- 

 tions; and (3) longitudinal and transverse strife in the interspaces of the pKcations. 

 Had there been more specimens at hand, it might have been even better to create a 

 new species. 



Horizon and Locality: Occurs with the preceding. Coll. C. C. Yii. (Ser. 

 No. X23U; Cat. No. 3367). 



5. Orthis carausii Salter, MS. 



PI. I, Fig. 6a-f. 



iSOy. Orthis cai-aiisii Salter, MS. Davidson, British Fossil Brachiopoda, Pt. \'1I, No. Ill, p. 229, pi. 

 XXXIII, figs. 1-7. 



This is represented l»y llie interior mold of the pedicle valve (Ser. No. X2U4, 

 IT. I, Figs. 6a, 61j) and the imijression of an exterior (Ser. No. X205. PI. I, Figs. 

 6c-6f). The former is semicircular and wider than high. The hinge line is at the 

 greatest width and a little prolonged, so as to gi\'e the suggestion of the presence 

 of ears at the cardinal extremities, which are acute. The valve is moderately con- 

 vex in the central region, the sides being comi)aratively depressed. The beak is un- 

 known, but a rostra] cone is present, which i.s slightly incurved and bounded on the 

 sides by two crescentic grooves. The surface is ornamented by about twenty-five 

 simple, rather angidar plications with wider inters})aces between. 



Measurements: 



Greatest width = 9 mm 



Hinge line =9 ,, 



Height - 6 ,, 



Pro}'urtion of height to width = l.-jt' 



