CLINTON GROUP. 
S3 
ACEPHALA OF THE CLINTON GROUP. 
The species of Acephala of this group are comparatively few, and they form no very con¬ 
spicuous palaeozoic feature of the strata. With the exception of a few localities, they are 
extremely rare, and I have not yet seen a single species west of Rochester. The shales below 
the iron ore bed in the eastern part of Wolcott have furnished more than all the other loca¬ 
lities ; while one or two species are quite common farther eastward, in the non-calcareous 
portions of the group. It is probable that other localities (were they accessible), between the 
eastern part of Oneida county and Wayne county, would furnish a greater number of species 
and individuals; but this portion of the formation lies in a low, level tract of country, scarcely 
accessible at all from natural exposures, and there are few artificial ones. We are warranted in 
this inference from the fact that in New-Hartford and Kirkland we find several species in con¬ 
siderable numbers, which are unknown in the localities in Wayne county, while these localities 
furnish other species unknown in Oneida county. We infer, therefore, not only from these 
facts, but from similar ones in relation to most of the Brachiopoda, that the species existing at 
the period of this deposition were limited in their geographical extent, and consequently every 
locality discovered will disclose new species. Those which we now present, therefore, can 
not be regarded as a full exposition of these forms in the group; and in the Acephala this 
period is less perfectly represented than in the Brachiopoda, which have been collected from 
a greater number of localities extending over a wider space. 
472. 6. AYICULA EMACERATA. 
Pl. XXVII. Fig. 1 a, b. 
Avicula emacerata. Conrad, Jour. Acad. Nat. Sci. Philadelphia, 1842, pag. 241, pl. 12, fig. 15. 
Avicula leptonota. Hall, Geol. Rep. 4th Dist. N. York, 1843, pag. 76, fig. 5. 
For description, see A. emacerata, Niagara group. 
The specimens examined thus far present no real difference from the Niagara species, and 
I have thought proper tq unite the two. The specimen figured in the Geological Report (Fourth 
District), has the form there represented ; but on a more careful examination, I am inclined to 
believe that it is distorted by pressure. Other specimens in the same soft shale are evidently 
distorted in a greater or less degree, scarcely any two individuals preserving precisely the 
same form. Those now figured from the Clinton group are scarcely at all distorted, and pre¬ 
sent so many features in common with the species in the Niagara shale, that I have referred 
them to the same. 
Position and localities. This species occurs in the ferruginous layers associated with the 
ore beds in Kirkland, Oneida county ; also in the shaly layers at Blackstone’s quarries, and in 
the soft shales below the ore bed in Wolcott, Wayne county. (State Collection.) 
