STRATIGRAPHY OF THE MIDDLE YANG-TZI PROVINCE. 279 
Girty regards this fauna. as Paleozoic rather than Mesozoic. He 
says :* 
The greatest doubt surrounds the highest of the supposed Carboniferous or Per- 
mian faunas, that which was found in a gray limestone interstratified with the red beds 
7 miles, 11 kilometers, south of Ta-ning-hién. From this horizon our collection affords 
only round crinoid stems. Dvzelasma (2), ef. D. elongatum, Aviculipecten (2) Richthofena 
n. sp., and indeterminable fragments of pelecypods. 
The little pectinoid described as Aviculipecten 2? Richthofeni is of a type which is 
common in the Paleozoic and doubtless in the Mesozoic as well. The cardinal structures 
and therefore the generic position can not be ascertained from our material. The Tere- 
bratuloid cited as Dielasma ? cf. D. elongatum has two large dental plates, but the struc- 
tures of the dorsal valve, which are usually more difficult to ascertain, have not been 
satisfactorily determined. I believe that it is not definitely known to what extent 
Mesozoic Terebratuloids develop plates in the ventral valve, but it appears to be rather a 
peculiarity of Paleozoic shells. Upon this point Waagen says, speaking of Hemiptychina: 
“The genus is distinguished very characteristically from the greater number of Paleozoic 
Terebratule by the absence of dental plates in the ventral valve. In this respect it ap- 
proaches more closely the Mesozoic forms, in which dental plates are nearly always absent.”’ 
(India Geol. Surv. Mem., Paleontologia Indica, Salt Range Fossils, Vol. I, p. 361.) 
It would appear from this that this type of structure is more common in the Paleo- 
zoic, though not entirely confined to faunas of that period. 
The evidence upon which the horizon in question is referred to the Paleozoic con- 
sists of the septiferous Terebratuloid, the round Crinoid stems, and the general Paleozoic 
complexion of the fauna. It is inconclusive and may not stand against any facts which 
strongly point to a Mesozoic age. For this reason my assignment to the Carboniferous 
is provisional only, and should the necessity arise of changing to a younger period, the 
readjustment would entail no serious conflict of evidence. 
The age of the coal-bearing strata at K’ui-chéu has been determined 
by previous observers as Triassic or early Jurassic. In 1866 Pumpelly 
brought thence a small collection of fossil plants,t which were submitted 
by him to Dr. J. 5. Newberry, who concluded that the fossils were most 
closely related to those of the late Triassic coal-measures of Virginia and 
North Carolina, and to certain Liassic forms of Europe. Collections made 
by von Richthofen at K’ui-chéuf and also others made by him and later 
by Léczy at Kuan-ytian-hién§ in the province of Ssi-ch’uan, were assigned 
by Professor Schenk to the Jurassic. 
White, after critical consideration of all the evidence thus far reported, 
confirms the original opinion that the K’ui-chéu plants are related to 
those of the European Rhetic more nearly than to any other known flora. 
His report follows. 

* Research in China, vol. 11. Paleontology. Report on Carboniferous Fossils, by George H. Girty. 
} Smithsonian Contributions to Knowledge, vol. xv, Geological Researches in China, Mongolia, 
and Japan, pp. 119-120. 
t China, vol. Iv, p. 266. 
§ Von Richthofen, China, vol. Iv, p. 265, and Loczy: Wissensch, Ergeb. der Reise des Grafen Béla 
Széchenyi in Ostasien (German edition) Il, p. 324. 
