34 BULLETIN IG-i, UNITED STATES NATIONAL MUSEUM 



Stercoplasmoceras is usually considered to be a characteristic genus of the 

 Toufangkou-Macbiakou limestone. Therefore Group III containing Stereo- 

 plastnoceras sp. appears paleontologically to be more closely related to the 

 Toufangkou-Machiakou series than to the Lianchiashan series containing 

 Piloceras fauna. 



It is quite clear from this that the Unkaku fauna includes forms 

 typical of the Ssuyen and Kangyao faunas. At the present time, 

 however, the question remains as to whether the "Wuting fauna is not 

 also included in Kobayashi's Unkaku or Bantatsuan fauna. 



Finally, the relationships of the Canadian and Ordovician faunas 

 in South Manchuria and North America should be discussed. Most 

 of the species described in this monograph are new, but are usually 

 closely allied to North American species. Only a very few are com- 

 mon to the two continents. The few identical forms and the large 

 number of allied species in these two widely separated regions, how- 

 ever, leave little chance for doubt as to at least the general correlation. 



The Manchurian Ssuyen fauna contains many cephalopods, such 

 as Ar?7ienoce7'as, Ormoceras, and Sactoceras, which have the very 

 characteristic features of Black River forms, in that they have com- 

 paratively broad actinoceroid siphuncles, and, of course, Maclurites 

 higshyi (Hall) and Maclurites nitida (Ulrich and Scofield) are 

 exactly the same as North American Black River species. Camaro- 

 cladia arhorescens, C. fucoides, and C 2?lana, which have been col- 

 lected from the top of the Ssuyen formation, are closely similar to 

 Oamarocladia dichotoma Ulrich and Everett and C. 7'ugosa Ulrich 

 from typical Black River beds. Since the uppermost horizon of 

 the Ssuyen formation, which has yielded Camarocladia^ is overlain 

 by Carboniferous variegated siliceous shales, and, furthermore, since 

 ^tromatoceriuTn regulatum, which makes up thick limestone beds 

 near the base of the Ssuyen formation, near Pen-hsi-hu, shows very 

 intimate relationships with Stromatoceriwn rugosum Hall, Koba- 

 yashi insists that the Tofango-Machiakou formations represent both 

 the Black River and Trenton groups of North America, According 

 to the evidence discussed above, however, it i^ quite apparent that 

 the Ssuyen is equivalent to the Black River and does not include 

 any Trenton. 



As most of the species from the Manchurian Wuting formation 

 are new or too imperfect for exact determination, it seems unde- 

 sirable to fix the age of the Wuting formation too definitely ; but the 

 general characters of the fauna are similar to those of the Athens 

 group of the Upper Chazyan in North America. Moreover, further 

 evidence for an Athens age of the Wuting lies in the fact that it is 

 always directly overlain by the Ssuyen. 



The Kangyao fauna of Manchuria is particularly characterized 

 by the abundance and variety of gastropods, chiefly Lophospira^ 

 which, of course, features the Mosheim group of the Stones River 



