WILLIAMS.] 
FAUNAL DISSECTION OF THE DEVONIAN. 
87 
Another method of determining the constitution of the Spirifer 
disjunctus fauna from statistics already gathered is that of analyzing 
a set of faunal lists, all of which contain Spirifer disjunctus. In this 
way the strict associates of that species will be given. 
As a convenient set of statistics (for this purpose) the fauna as 
reported in Bulletin 41, for the Genesee section in western New 
York may be taken. 
Of these faunules there are 16 containing Spirifer disjuncUis. In 
the following table are listed the more frequent associates of that 
species. The number in the right-hand column indicates the number 
of times eacli species is reported in the 10 faunules. 
Table XXII. — The Spirifer disjunctus fauna, with its more dominant associate*, 
as represented in the Genesee section. 
1. Spirifer disjunctus 
2. Camarotcechia contracta . 
3. Orthothetes chemnngensis 
4. Athyris angelica . . . 
5. Chonetes scitulus - 
6. Productella hirsuta 
7. Mytilarca chemnngensis 6 
8. Sphenotns contractus 5 
9. Orthis (Dalmanella) leonensis_- 4 
10. Orthis (Schizophoria) impressa^ 4 
1 1 . Ambocoelia nmbonata 4 
12. Prodnctella costatnla 4 
The first 7 species of this list are among the standard forms deter- 
mined by the first method and listed in Table XXI, and all of them 
except the eighth are actually in that group of 20 species, but several 
species obtained by the other method are not mentioned in this list 
simply because, though common species, they did not appear conspic- 
uously in faunules actually containing Spirifer disjunctus, though 
present in the same general fauna to which that species belongs. 
In the original volume describing the brachiopods of the Devonian 
of New York a the following localities are mentioned in which Spirifer 
disjunctus occurs, viz: Elmira, Leon, Painted Post, Factoryville, 
Cayuta Creek, Chemung Narrows, Conewango, Great Valley, Ran- 
dolph, Napoli, New Albion, Chemung, Bath, Angelica, Troupsburg, 
Meadville, Pa., Twentymile Creek, Ellington, Glean, Covington, Pa. 
From these localities the following species are recorded for the num- 
ber of localities indicated : 
Table XXTIa. — Species listed from same localities with Spirifer disjunctus in 
New York reports. 
Camarotoechia contracta - 10 
Orthothetes chemnngensis. - - 3 
Athyris angelica . - 3 
Prodnctella hirsuta and var - 1 "* 
Sphenotus contractus 2 
There are other species mentioned in the published lists, but from 
each locality the number of species is limited, rarely over 20 and 
generally under 10. The collections show in themselves that the con- 
spicuous species were gathered, or perhaps the fine specimens only 
a Palaeontology New York, Vol. IV, 1867. 
