BEEDE AND ROGERS.| Coal Measures Faunal Studies. B25 
here elevated to the rank of species. The two, the variety and 
the species, are associated in the lower rocks, but the “variety” 
replaces the species in the upper rocks. The little shell is so 
characteristic of the whole Kansas section that it is worthy of 
specific rank without question. The fossil provisionally iden- 
tified as Seminula subquadrata Hall, from the Pawnee lime- 
stone, is a worn, imperfect specimen of questionable identity. 
It may be the same species as that identified by Doctor Bennett 
as A. trinucleus from this horizon. 
The Fauna. 
The fauna as a whole is made up as follows: 
Foraminifera, 12 species. Scaphopoda, 1 species. 
Spongiz, 5 species. Gastropoda, 51 species. 
Anthozoa, 10 species. Pteropoda, 1 species. 
Crinoidea, 28 species. Cephalopoda, 26 species. 
Ophiuroidea, 1 species. Trilobita, 3 species. 
Echinoidea, 8 species. Ostracoda, 15 species. 
Vermes, 2 species. Merostomata, 7 species. 
Bryozoa, 47 species. Insecta, 13 species. 
Brachiopoda, 46 species. Vertebrata, 13 species (in the 
Pelecypoda, 111 species. chart. Plate XLII). 
While the brachiopods are fourth in the list with respect to 
the number of species found, nevertheless the fanua as a whole 
is distinctly a brachiopod fauna, so far as the number of speci- 
mens to be noticed are concerned. While the pelecypods con- 
tribute nearly a third of all the invertebrate species to the 
fauna, yet, with few exceptions, they form but a very 
small percentage of the specimens of any faunule. The Mof- 
lusca contribute practically half the species found, though 
rarely can a faunule be said to be mollusean. It is not until! 
near the top of the section is reached that the Mollusca finally 
assume supremacy over the Brachiopoda, never to relinquish it. 
Aside from the Fusuline the Productidsz contribute more to 
the make-up of the faunules than any other family. After the 
Productidz come the Spiriferidx and the Athyridse as chief 
causes of the faunal coloration. 
The Correlation Value of Species. 
For purposes of correlation certain species are of much 
more value than others. The ones of greatest value are those 
of wide distribution and short range, as Chonetes mesolobus, 
N. and P., Chetetes milleporaceous M., E. and H., Schwagerina 
princeps (Moell.) and others. With the exception of certain. 
limitations mentioned later the chart shows what species are 
