122 
GEOLOGY OF THE THIRD DISTRICT. 
No. 4, is another species, which may be considered as the type or characteristic of the 
division, and thence may properly be termed the Medial atrypa (A. medialis), the others 
diverging or converging from this middle point. Size natural. 
27. 
No. 5. Punctulated strophomena (S. punctulifera). No. 6. Radiated strophomena (S. radiata). 
There are two species of strophomena in this rock, which are very numerous, and by which 
the rock may in many of its localities be readily determined. They abound through its range 
in Herkimer county, associated with the Smooth atrypa, the Medial atrypa, and the Depressed 
strophomena, which latter reappears in this rock from the Niagara group, not having been 
seen in the intermediate ones in the district. The internal impression of the two fossils in 
question are given, by reason of their greater abundance than the shells themselves, and espe¬ 
cially as these latter will with certainty be figured in the Report on the Fossils of the State. 
The following list presents all the fossils belonging to this rock, which have been identified 
and named by Mr. Conrad up to this time : 
Shells. 
Testacea, or 
Delthyris macropleura. 
Delthyris pachyoptera. 
Delthyris granulosa. 
Delthyris bilobata. 
Orthis resembling the resupinata. 
Strophomena punctulifera. 
Strophomena rugosa (the depressa). 
Strophomena radiata. 
Strophomena indentata. 
Atrypa resembling the concentrica of the 
Hamilton group. 
Atrypa prisca. 
Atrypa inflata. 
Platyceras ventricosum. 
Platyceras gebhardii. 
Calceola plicata. 
Conularia quadrisulcata 
Tentaculites scalaris. 
CORALEA, OR CORALS. 
Calamopora favosa. 
Asaphus pleuroptyx. 
Asaphus nasutus. 
Ascidopsis tuberculatus 
Crustacea. 
Acanthaloma, not determined. 
Dicranurus, ditto. 
