46 CORRELATION OF GEOLOGICAL FAUNAS. [bull. 210. 
the Survey in 1883, before the field work of that year was begun. 
The field work of 1883 and 1884 was planned as a continuation of this 
earlier work in and south of Ithaca which had been conducted pri- 
vately as a part of the work of a professor of Cornell University, and 
it was carried on under the auspices of the U. S. Geological Survey 
in the Genesee Valley. The report on this work was published as 
Bulletin 41 of the U. S. Geological Survey, the manuscript of which 
had been sent in on August 2, 1886. A preliminary report of the 
results of the summer's work along the Genesee Valley was prepared 
at some length and sent to the Director. This paper was received by 
the Director July 27, 1884, and is numbered 1398 of correspondence 
of 1884. An abstract of it is published in Science, Vol. II, pp. 836, 
837, dated December 28, 1883. 
At first the report was intended for publication in the annual report 
of the Director, but was returned for enlargement into a bulletin and 
formed a basis of the report finally published as Bulletin No. 41. The 
paper sent to the Director in 1884 contained a classification of the 
successive faunas observed on passing across the State from Wyoming 
County, N. Y., the examination extending as far as the southern part 
of McKean County, Pa. 
Bulletin No. 41, on the Genesee section, was published in the year 
1887. It was written after two more years of field work had carried 
the studies westward, as well as eastward, from the initial section at 
Cayuga Lake. In 1884 the sections from Chautauqua Comity, N. Y., 
to Cleveland, Ohio, were investigated, and in the following summer 
(1885) sections across the corresponding part of the formations were 
run from Chenango County to Delaware and Otsego counties. 
In the report as published in Bulletin No. 41 the faunal zones 
recognized were as follows: 
1. Lingula fauna (sec. 468, p. 31). Genesee formation. 
2. Car diola fauna (sec. 472). Portage formation. 
3. Early Leiorhynchus fauna (sec. 476 G). Green shale of Chemung. 
4. Spirifer mesicostalis fauna (sec. 476, p. 58). Rushford shale. 
5. Streptorhynchus and Spirifer disjunctus fauna proper (sec. 477, p. 65) . Cuba 
sandstone. 
6. Lingula fauna (second; sec. 477 A 2, p. 64). 
7. Lamellibranch fauna (sec. 477 A 3, p. 64). 
8. Athyris angelica fauna (sec. 477 H, p. 67). 
9. Flat-pebble conglomerate; Palaeanatina typa (sec. 486). 
10. Ferruginous sandstones; Rhynchonella allegania (sec. 484. p. 87). 
Two important subfaunas, local in extent, were also recognized, 
viz, the Centronella julia fauna of Rushford, in the midst of the zone 
covered by the Sjoirifer disjunctus fauna, and the Orthis leonensis 
zone south of Cuba (p. 34). On the same page it was stated that the 
several faunas do not indicate particular geological horizons, but par- 
ticular conditions of environment or habitat, which, locally, had defi- 
nite place in the column. Each of the faunas was dissected as it 
occurred in its own section of the formations (p. 38). 
