STRATIGRAPHY OF THE MIDDLE YANG-TZI PROVINCE. 271 
While following this horizon southeastward along the strike of the 
syncline, we found fossils again abundant near the mouth of the ravine 
immediately northeast of Sii-kia-pa. Here, as before, the fossils occurred 
in gray limestone associated with green shales, and it is evident that the 
horizon is equivalent to the one just described. It is, however, a matter 
of surprise that the two lots collected have so few specimens in common. 
The list from this locality comprises: 
Strophomena sp. Bathyurus sp. 
Triplecia polot Martelli Asaphus sp. (cf. Asaphus expansus Dalman) 
Orthis calligramma Dalman Asaphus asvaticus Weller 
Dalmanella testudinaria Dalman  Asaphus chinensis Weller 
Dalmanella subequata Conrad Asaphus sp. (several indet.) 
Plectorthis willist Weller Isotelus sp. (hypostoma) 
Chitambonites chinensis Weller Isotelus sp. (pygidium) 
Hemipronites tenurstriata Weller = Illenus (2) bronteotdes Weller 
Gastropod indet. Pretus (2) sp. 
Cyrtodonta (2) sp. Calymene (2) sp. 
Ampyx chinensts Weller Pterygometopus (2) sp. 
South of Sti-kia-pa, where the river passes through a box canyon, this 
fossiliferous horizon dips beneath higher Paleozoic rocks, and does not 
reappear until the Yang-tzi river is reached. In the lower gorges of the 
great river the formation is exposed in several places, but our journey was 
too rapid to permit of any further search for fossils. 
Just above Ta-miau-ssi, Ssi-ch’uan, atlas sheet d 6, the lower thin- 
bedded portion of the Ki-sin-ling formation reappears, probably for the 
first time north of the Yang-tzi gorges. The rocks consist of an alterna- 
tion of brown, gray, and black slaty limestones among which are black 
oolites not unlike the Ch’ang-hia oolitic limestone of Shan-tung and the 
corresponding Middle Cambrian oolites of northern Shan-si. No fossils 
were found in this series, but inference based on the structure and the 
occurrence of the black oolite indicates that the beds are Cambrian. 
On the northern slope of the divide between Ssi-ch’uan and Shen-si, 
and south of Chén-p’ing-hién, the Ki-sin-ling limestone is exposed in two 
large anticlines bounded by synclines in the Sin-t’an shales. In this 
locality the Middle Ordovician shaly horizon, which was observed near 
Sii-kia-pa and described above, appears to be represented by continuous 
limestones, and fossils of that age were not found. The Nan-kiang, along 
the canyon of which we ascended toward the Ki-sin-ling pass, did not 
appear to have cut sufficiently deep into either anticline to expose the 
base of the system, but in the shingle of the river a mile above Chén- 
p’ing-hién, we found pebbles of gray-green oolitic limestone, pisolitic and 
