132 LA TOUCHE : GEOLOGY OF NORTHERN SHAN STATES. 



sections as occur are generally inaccessible on account of the dense 

 vegetation, the exact horizon from which the fossils have been derived 

 can very seldom be ascertained. 



Starting from the western edge of the plateau, the first point at 

 which these beds are met with is the locality 

 Outlier on Memauk already mentioned, on the crest of the Memauk 

 spur ' spur, overlooking the valley of the Chaung- 



Magyi at Aunglok (Loc. 47, B 4). The occurrence here is completely 

 isolated, the sandstones occupying a very small area surrounded by 

 older rocks, on which they rest unconformably (Section II, Plate 23). 

 At the eastern end of the exposure the rocks beneath them are the 

 upper Naungkangyi variegated shales, dipping apparently at high 

 angles, but at the western end these are absent, and the Namhsims 

 rest directly upon the much older rocks of the Chaung-Magyi series, 

 also highly inclined. At the extreme western end of the ridge 

 the basement beds of the Namhsims are seen, 



Conglomerates at base. . , . . , 



consisting ot very coarse conglomerates, m 

 which boulders and pebbles of the Chaung-Magyi quartzites pre- 

 dominate, mingled with a few from the crystalline series of Mogok, 

 which is in situ on the further side of the Chaung-Magyi valley. 

 The conglomerates pass upwards into a series of rather coarse- 

 grained, blue and purple, felspathic grits and sandstones, in the 

 more fine-grained layers of which the fossils occur. The horizon 

 of these, therefore, is not far above the base 

 of the series. They comprise Mimulus aung- 

 lohensis Reed ; Orthis sp. ; Orthonota(1) spectabilis Reed ; two un- 

 determined species of Proetus ; and Cheirurus (?) inexpectans Reed. 

 Of these Mimulus aunglokensis occurs in considerable numbers ; 

 the genus is confined to the Bohemian area, except for one species, 

 M. waldronensts Miller and Dyer, from the Niagara group of N. 

 America. In Bohemia it occurs in Etage E 2, corresponding to 

 the Wenlock formation in England, and the Bohemian M. con- 

 trarius Barr. bears a considerable resemblance to the Burmese form. 

 The Orthis is in too poor a state of preservation for specific de- 

 termination. The genus OrtJionota is characteristically Silurian, but 

 species have been described both from Bala and Devonian rocks. 

 In America Ortlionota s. s. t is confined, according to Hall, to the 

 Hamilton and Chemung groups, or middle and upper Devonian, but 

 the Burmese species bears some resemblance to Sanguinolites (Or- 

 tlionota) decifiens McCoy, from the upper Ludlow. Ill-preserved 



