(i) (3 Pa1ii oiitolo;iixi Siiiiva '5<-'\ B 



and 58 species 45 of tlieso liL-ing six'cifically identified.* All except five of the species are 

 new. Tln-ee new genera, and a new family of cephalopods, that nf the Cluhliocerafidiv are 

 described. 



STRATIGRAPHIC SUMMARY. 



Willis and Blackwelder applied the name Tsinan formation to the entire 

 Ordovician series of North (.'hina, which they regarded as a unit. The name was taken 

 from Tsi-nan-fu in Shantung near which the upper beds of the series are well exposed. It 

 is now known that there are several Ordovician formations in north China, with probably 

 a disconformity between the higher and the lower divisions. The base of the Ordovician 

 lias been definitely located in the vicinity of the little hamlet of Yehh, about 9 li or about 

 3.6 miles east-north-east of Machiakou in the Kaiping Coal Basin. Here the Ordovician 

 beds rest disconformably upon the Upper Cambrian or Cambro-Ordovician transition 

 beds, the Fnvjsluni formation, which carries a fauna recalling the Cenitopyge fauna of 

 Europe, including a new species of Ceratopyge. The disconf<jrmity is marked by an 

 irregular erosion surface of the l^^Ongshau formation followed l>y a basal conglomerate 

 which marks the lieginning of the Ordovician limestones **). 



To the limestone immediately succeeding this l>asal conglomerate we have given 

 the name Yehli formation, and from it the following species have been obtained. 



CEPHAT.OPODA 



Succoceras iicJdiensc Grabau 

 Siirrorcra>< attcnuaUun Grabau 



Extremely meager as this fauna is, it is sutficient to indicate early Ordovician, 

 but whether it is Lower or early J\liddle Ordovician must for the ])resent remain undeter- 

 mined. The bmestones of this region have a total thickness, according to the measure- 

 ments of Mr. H. C. T'an, of approximately 800 meters, but whether this series is 

 continuous or separated into two divisions liy a hiatus, has not yet lieen ascertained. 



VITKR ORDOVICIAN 



The upper l)eds of the Ordovician of the Kaiping basin arc well exjM^sed at 

 Machiakou, south-west of Yehli, and from this locality the formation is named the Machia- 

 Icou divisiini or Machiakou formation. This is the tyi)ical Actinorera>< limcxfoiie, widely 

 exposed in the Kaiping liasin from Cliae)kouchuang on the east t(j Tangshan on the west. 

 It is again known l)y fossils from the Western Hills of Peking, from the Shansi border. 



*) This includes two varieties. Tvro others have been tentatively referred to known species. 

 **) Thia will be described by the author in the Bulletin of the Geological Survey. 



