SILURIAN SYSTEM: ZEBINGYI STAGE. 



167 



Beneath the Zebingyi plateau the rocks form a shallow syn- 



_ , . . clinal, bending up again to the east with a 



Zebingyi synclinal. , ,. ,. . , , , 



westerly dip, so that, about a mile to the 



east of the station, the graptolite beds reappear from beneath the 



Plateau Limestone. The section here (Zebingyi 2 of Mr. Cowper 



Eeed's Memoir) (Loc. 39, B 5) is a very poor one, exposed partly 



in a small cutting, and partly in the drainage channels on either 



side of the line, and differs in some respects from that west of the 



station. The black earthy limestones are very much diminished 



in thickness, and most of the graptolites occur in light grey shales.. 



but they are in a better state of preservation and more numerous 



than at the former locality. The grey thin-bedded limestones and 



shales beneath them have also disappeared, and the only limestone 



to be seen is a hard, nodular, lenticular mass, crowded however 



with casts of Orthoceras, but so completely weathered that most 



of them crumble into dust on being extracted. The fossils col- 



lected here were : — In the graptolite shales. 



Monograptus dubius ; Meristina sp., a trans- 

 versely oval shell referred with some doubt to this genus, which is 

 a Niagara or Wenlock form ; an undetermined species of Modio- 

 lopsis ; abundant specimens of Tentaculites elegans ; and a single 

 example of another species, compared with T. ornatus Sow., from 

 the Wenlock beds of England. The rings on this species are fewer 

 in number and wider apart than in T. elegans, and the interspaces 

 are broad and marked with fine concentric striae. The fossils 

 collected in the underlying limestone were Lindstrcemia sp., similar 

 to those found at Pomaw in the Gokteik gorge, and the same 

 species of Orthoceras that occur at the locality below Zebingyi 

 including the specimens of 0. aff. vwcklreense and 0. aft", com- 

 mutatum figured in Mr. Reed's Memoir (PI. VII, figs. 9, 11, 12). 

 The limestone also contains the pygidia of a small trilobite, pro- 

 bably of Phacops shannsis Reed. 



The axis of the Zebingyi synclinal is inclined to the north in 



such a manner that the outcrop of the Zeb- 



Linnts of outcrops. . . . ,,, ■ L 



ingyi beds describes an elliptical curve, ex- 

 tending southwards to the village of Pebin, between Zebingyi 

 station and the Mandalav Mavinvo cart road. At IVbin the beds 

 axe very thin, and they evidently died out rapidly in this direc- 

 tion. The northern side of the Zebingyi plateau is bounded by 

 inaccessible cliffs of limestone, al I he base of which in the Scdaw 



