ORDOVICIAN SYSTEM: UPPER NAUNGKANGYI STAGE. 



bend from north to west near Man-Loi (D 3), west of Pyaunggaung 

 station. Here they reappear on the right ba n k of the river, and 

 are fairly well exposed at Hweyawt (Loc. 95, J) 3), where Pliomera 

 ingsangensis is very common, as well as plates of Caryocrinus sp. 

 Hence they continue up the right bank of the Nam-Tang to the 

 bend north of Nam-saw, and are found on the lower slopes of 

 the hills north of this village, on the zig-zags of the cart road leading to 

 M6ng-L6ng (Loc. 94, J) 2). At this locality there has been a great deal of 

 faulting and other disturbance of the strata, and it is by no means 

 easy to make out their relations with each other. 



Between this point and the ravine of the Nam-non, east of 

 Kunkaw, the upper Naungkangyi beds are 

 exposed only in patches, as inliers surrounded 

 by higher formations. One of these occurs in the ravine imme- 

 diately south of Kiohsio (S) (E 2), and extends across the ridge west 

 of that place to the site of the deserted village of Ingsang (Loc. 

 93, D 2), which has given its name to the little trilobite Pliomera 

 ingsangensis, so common in these beds. Besides this species, 

 the fossils collected here included Rafinesquina subdeltoidea Keed, 

 Plectambonites sericea Sow., Encrinurus sp., and Sfhwrocoryphe sp., 

 as well as numerous plates and the detached arms of cystideans. 

 Only single and very minute specimens of the other two trilobites 

 were found, that of Encrinurus being a. pygidium only 2 mm. in 

 length ; while Sphcerocoryphe is represented by a cast and impression 

 of a head-shield about 4 mm. in length. Mr. Keed compares it 

 with S-ph. Hubneri Schmidt, from Stage C 3 of the Ordovician of the 

 Baltic Provinces. The genus appears to be confined to the northern 

 marine zoogeographical provinces in Europe. 



The upper Naungkangyi beds occur in the deep ravine 



„ east of Kiohsio leading down to the Nam- 



Nam- lu valley. . • i p 



hsim, but the sides of the ravine are so 



densely clothed with jungle that it was found impossible to trace 



the boundaries of the formations with any degree of accuracy 



here. They are overlapped by higher beds in the gorge of the 



Nam-hsim, but are found on both sides of the Nam-non ravine, 



about Kunkaw on the west and Nam-yun on the east. They 



appear again on the Panghsa-pye saddle, and from this point may 



be traced almost continuously down to the gorge of the Nam-Tu. 



They are very well exposed on the spurs to the west of the river 



and in the bed of the river itself, and large collections of fossils 



