ORLOVICIAN SYSTEM : NYAUXGBAW LIMESTONES. 



123 



the Camarocrinus beds of America, corresponding to Etage F in 

 Bohemia or the Lower Devonian, and to be more closely connected 

 with the underlying Naungkangyi than with the overlying Zebingyi 

 beds. 1 



The Nyaungbaw Limestones have not been found further east 

 Possible representa- tnan tn ^ s > unless, as ^ possibly the case, they 

 tives in the Eastern are represented by the purple band at the 

 top of the Naungkangyis in the Nam-Tu 

 valley, and by the upper part of the Hwe Mawng beds in the 

 eastern ranges. Certainly the limestones, which form a part of the 

 purple zone, resemble them very closely ; and in the far east, on 

 the Nam-hen between Pinghsai and Kehsi Mansam, and again on 

 the Nam-Pung, a tributary of the Nam-Pang, in South Hsenwi, 

 there are some limestones, quite at the top of the Hwe Mawng 

 beds, which, as far as lithological appearance goes, are identical. 

 But in the absence of any direct rjalseontological evidence of iden- 

 tity, — -for neither Camarocrinus, nor indeed any recognisable fossil, 

 except crinoid fragments, have been found in these eastern beds, 

 — their correlation with the Nyaungbaw limestones of the west must 

 remain doubtful. 



* Prof. Sehuchert, to whom I submitted the manuscript of this portion of my 

 Memoir, has very kindly sent me some notes on the position and relationships of 

 Camarocrinus. He was at first sceptical as to the stratigraphica! horizon attributed by 

 me to these beds, as he thought t hat 1 he evidence of unconformity between the Nyaung- 

 baw and Zebingyi beds was not convincing: but he now accepts the statement that the 

 discovery of C. asiaticus in the limestones to the north of Maymyo, on the same strike 

 as those with Diplotrypa palinensis, LinguJaci. qvadrata, and Orthis irravadica, which 

 was not known to him r.t the time that his criticism of Mr. Cow per Reed's Memoir was 

 written, indicates the Ordovician age of the Nyaungbaw Limestone. He still thinks, 

 however, that until more direct evidence of the association of Camarocrinus with 

 Scyphocrinue is forthcoming, it cannot be inferred that this was the only crinoid 

 that was furnished with these floats. One objection to the supposition that these 

 bodies served as the floats of crinoids does not appear to have been noticed, viz., the 

 presence of pores at the margin of each plate forming the test. These arc not shown 



