128 LA TOUCHE : GEOLOGY OF NORTHERN SHAN STATES. 



F 1), but in a very soft, decomposed condition. Better preserved 

 specimens, in large numbers, may be collected at the village of Ngai- 

 tao (Loc. 64, F 1), on the spur above Ta-pangtawng. The most 

 important form is Monograptus gregarius Lapw., the zone fossil of 

 the upper division of the Lower Birkill shales. With this are 

 associated Rastrites peregrinus Barr. and Climacograptus Tdrnquisti 

 E. and W., which are, according to Miss Elles, also characteristic 

 of the zone of M. gregar ius. Diplograptus (Mesograptus) modest us 

 and Monograptus cyphus var. minor Lapw. are also to be found 

 here. We have thus two well-defined horizons of the Lower 

 Llandovery represented in the Nam-Tu valley ; but it remains to 

 be seen whether they are actually situated on two distinct strati- 

 graphical planes in this area ; and this can only be done by 

 careful search throughout the whole thickness of the beds exposed 

 in each section. 



Further north again, beyond the limits of the map, graptolites 

 were found by Dr. J. M. Maclaren in a simi- 



Nam-pang-yun. . . . T< , 



lar position on the JNam-pang-yun, about a 

 mile above its conflux with the Nam-Tu, on the way to the 

 Bawdwin silver mines. Here they occur in a black, carbonaceous 

 sandy shale, and are very ill-preserved, in fact only just recognisable 

 as graptolites. 



The graptolite band is met with again among the hill ranges east of 

 the plateau, resting upon the purple Hwe-Mawng 

 Occurrence in East- beds. In the Loi-len range, east of Lashio, 

 em Loi-len range. it was found on the south slope of the ridge 



about two and-a-half miles E.N.E. of the village of Pangme (Loc. 66, 

 HI)- At this locality the graptolites occur not only at the top 

 of the purple beds, but also in some white shales interbedded with 

 the latter. A species of Climacograptus is the most common form 

 that was found here, but time did not allow of a thorough search 

 being made, or of a second visit to the locality. Further to the 

 south the graptolite shales have not been detected in any of 

 the sections exposed along the flanks of Loi Ling, or among 

 the hills east of Mong-Yai, but a small outcrop was found at 

 ( the top of the Hwe-Mawng beds forming the 



dome-shaped mass of hills between Loi Ling 

 and Mong-keng, close to the small village of Nam-hsim (J 2) 

 They reappear, however, in the same position on the eastern 

 flanks of the Loi Pan range in Kehsi Mansam, between Mong- 



