ORDOVICIAN SYSTEM : LOWER NAUNGKANGYt STAGE. 



83 



Illcenus, Cheirurus, Harpes, and Asaphus, but the species belonging 

 to these genera have not yet been determined. 



An outlier of the Ordovician rocks occurs to the west of this 

 band in the valley of the Nam -hen, occupying a synclinal fold in 

 the Chaung-Magyis, and surrounded by a narrow band of the lower 

 Naungkangyi beds. 



A fault runs along the valley of the Nam-hen, truncating the 

 little synclinal just mentioned, and shifting 



East side of Loi Twang;. , , , r . , T , 



the Man-pun band or lower Naungkangyis 

 to the eastwards. It is found again on the south bank of 

 the river at a point where the latter makes a sharp bend to 

 the south about two miles above the village of Ping-hsai (H 

 4), whence it extends to the south-south-east, across the flanks 

 of Loi Kok, to the village of Hwe-wa, (Loc. 107, K 5), three miles 

 west-north-west of the town of Kehsi Mansam, where another fault 

 occurs, shifting it westwards again for about the same distance as the 

 Nam-hen fault does. It then continues in the sime direction, along 

 the base of the Loi Twang range, its course being marked by a series 

 of narrow valleys and depressions, through the village of Hwe-Mawng 

 (H 5) to the eastern side of the Loi Pamong ridge. Its southerly 

 extension has not yet been traced beyond 

 this. Fossils of the same species as those 

 enumerated above from near Man-shio may be found wherever an 

 outcrop occurs, but they are as usual greatly distorted and crushed, 

 and the beds are in most cases either vertical, or tilted up at high 

 angles, and in some places even inverted. Among these fossils the 

 new trilobite Calymene birmanica has been detected by Mr. Cowper 

 Reed in a small collection from. Loi Kok (Loc. 106, H 5), and the 

 brachiopod Orthisina ascendens Pander in that from the flanks of 

 Loi Pamong (Loc. 108, H 5) ; this is a lower Ordovician form 

 from the Kuckers beds of the Baltic Provinces. 



Although the lower Naungkangyi beds have been found to rest 



. , . . directlv upon the unfossiliferous rocks of the 

 ( onditious ot deposition. m " t» i i- 



lawng-Peng system wherever t!>e line of con- 

 tact is exposed, and the unconformity between them is usually well 

 marked, no traces whatever of conglomerates, or even of sand- 

 stones, coarse or fine-grained, are met with among them, nothing, that 

 is to say, which implies the presence of dry land in the immediate 

 neighbourhood at the time of their deposition. They appear to have 

 ,been laid down in the open sea, perhaps in a sea of not very 



g2 



