RAYMOND: CORRELATION OF THE ORDOVICIAN STRATA. 263 
to spend a few days on the work. The study of the collections is still 
incomplete, and considerable field-work remains to be done before any 
satisfactory correlation can be made, but the preliminary results seem 
to indicate a correlation with the formations in Kentucky rather than 
with those in New York. The important fact, mentioned before, of 
the identification of the fauna of the Leray-Black River in the strata 
just above the pure quarry rock gives a datum plane for correlation. 
Above this zone, but still in the strata called “ Black River” by Collie, 
is found the fauna with Echinosphaerites, and in the lowest “Trenton” 
(A 8 of Collie), one finds fossils such as Cryptolithus tessellatus, Orthis 
tricenaria, Dinorthis, and others which suggest the Hermitage of 
Kentucky. The “Trenton” has a thickness of 600 feet, and at the 
top, Cryptolithus comes in a second time, as in the Cynthiana of 
Kertucky. In our present state of knowledge, it must be confessed 
_ that the thickness of the section, the general likeness of the faunas, 
and the two occurrences of Cryptolithus, are the principal bases on 
which the correlation is made. So far the upper Echinosphaerites 
zone with Christiania has not been found at Bellefonte, but the general 
similarities of the sections at Chambersburg and Bellefonte are such 
that we fully expect work in the intervening areas to establish a fairly 
secure correlation between them. 
GENERAL DISCUSSION OF RUSSIAN EARLY ORDOVICIAN 
FAUNAS. 
The correlations attempted above have been based largely upon 
stratigraphic position and “guide fossils.”” It remains to compare 
in a little more detail the faunas of the strata which have been corre- 
lated. 
WaALCHOW AND KUNDA FORMATIONS. 
The part of the correlation which I must most justify to American 
students is, probably, that in which I agree with most Continental 
authors, in assigning the Walchow and Kunda formations, B,, and 
B,,,, to the horizon of the American Beekmantown. Therefore, I 
wish, in addition to what has already been brought out, to discuss the 
faunas of these two formations in some detail. Bassler has correlated 
the two formations, in a general way, with the lower part of the Black 
