38 RESEARCH IN CHINA. 
The lower limestones and shales are followed by a second argillaceous 
member, in which green nodular shales alternate with slabby blue lime- 
stones, locally conglomeratic, through a vertical range of about 150 feet, 
45 meters. In the upper part of this member there are greenish platey 
limestones, which produce talus slopes covered with hard thin plates of 
rock. ‘These were known in the field as the ‘‘swallow slates,’”’ from the 
fact that the weathered surfaces expose large numbers of pygidia of the 
trilobite Drepanura premesnili Bergeron, which bear a fanciful resem- 
blance to swallows in flight. 
The remainder of the Kiu-lung group is composed of a variable 
succession of limestones having a thickness of over 500 feet, 150 meters. 
Although they are mostly thin-bedded and often slabby, two relatively 




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Fic. 10 (Blackwelder).—Yen-chuang, Shan-tung. Section of Kiu-lung formation in Kiu-lung-shan. 
1 = Man-t’o shales; 2 = dark limestone, partly oolitic; 3 = dense gray limestone; 4 = nodular green 
shale; 5 = dense gray limestone; 6 = gray shale and slabby limestone; 7 = thin-bedded dense 
gray limestone; 8 = green calcareous shale; 9 = conglomeratic limestone; 10 = nodular green 
shale; 11 = slabby blue limestone; 12 = shaly limestone and gray shale; 13 = black limestone; 
14 = slaty gray limestone; 15 = conglomeratic limestone; 16 = massive gray limestone; 17 = 
thin-bedded gray limestone; 18 = red conglomeratic limestone; 19 = dark gray limestone, locally 
conglomeratic; 20 = massive gray limestone. 
massive members produce cliffs. Dense hard blue-gray limestones pre- 
dominate over the granular layers. Conglomeratic strata, which occur at 
many horizons, are identical in appearance with both the red and the 
brown phases observed near Ch’au-mi-tién. In the uppermost beds of 
the formation one often finds concentric structures which are developed 
by weathering into features which, in size and appearance, are not unlike 
transverse sections of cabbages. Although they have the aspect of concre- 
tions, they are not composed of any foreign material; they are an integral 
part of the limestone itself. Similar structures are known from the 
Algonkian limestones of Montana in the northwestern United States. 
In these upper limestones fossils are only moderately abundant, and 
are usually not well preserved. Those which are present agree essentially 
with the faunas of the Ch’au-mi-tién formation in the type locality. 
Fossils from the lower limestone.—In the mountains southwest of 
Yen-chuang, a small lot of fossils was collected from the greenish gray 
