1895. | NEW YORK ACADEMY OF SCIENCES. 87 
25-30. Compact heavy, nearly barren layers, having 
conchoidal fracture, with intervening shale, the latter 
containing fragments of :— HOB» ,9"” 
Prasopora. Lingula curta. 
Crinoid columns. Orthis testudinaria. 
Asaphus platycephalus. Orthoceras. 
31. Impure black, breaking irregularly, with calcite 
seams and afew comminuted fragments of fossils in 
the purest portion. |g a 
Crinoid fragments a. Calymene senaria. 
Orthis testudinaria. Rafinesquina alternata. 
32-33. At the falls near the upper bridge, impure 
black limestone ; the only fossils being scattered Orthis 
and Asaphus fragments. Li! oY 
CONCLUSIONS. 
Reference to the faunal lists, facilitated by the appended tabu- 
lation, suggests several features. 
First : The almost universal prevalence of Orthis testudinaria 
Rafinesquina alternata, Plectambonites sericea, Orthoceratites, 
Asaphus platycephalus and Calymene senaria throughout the 
formation. 
Second: The much greater number of forms found in the 
Black River zones, and in general also in the lower zones than 
in those above. 
Third: The prevalence of Crinoids, Prasopora, Rhyncho- 
trema inequivalvis and Trinucleus concentricus, principally 
in the lower layers. 
Fourth: The appearance of Parastrophia hemiplicata so high 
up in the series in B 14. 
Fifth: The first appearance of Acidaspis Trentonensis, as- 
sociated with the most perfect fallen remains of crinoids 
found, in the uppermost portion, in the shaly partings of the 
comminuted gray limestone, suggests that the crinoids and the 
trilobites were killed by the same inflow of muddy water into 
the purer seas. 
Sixth: The absence of various typical Trenton species of fre- 
quent occurrence in other localities and not found among the 
material collected, indicating that they are at least not abundant, 
if they indeed occur in the region. Some of these species are 
Climacograptus, Solenopora compacta Bill, Orthis occidentalis 
Hall, O. tricenaria Dalman, O. subquadrata Hall, Leptena 
rhomboidalis Wileck, Rhynchotrema capax Con., Cyclospira 
bisulcata Emmons. 
