Geology. 277 
palliata, Cardium Groenlandicum, Cardium 
}}, SAF Behenae nrcenatiint: 
PL 
Hameri (abundant), Mya truncata, Sazicava rugosa, Astarte Lauren- 
tana, Trichotropis borealis and Buecinum undatum. The bed—of hard- 
ened clay—was probably formed in deep water. 
At the terraces of 220 and 386 feet on Montreal mountain no shells 
orknean found. But westward of Montreal, near Kemptville, Sir W. 
rugosa, 53 feet; (3) 6 Ps of stratified sand with few shells. On the 
Ottawa, in the 4th concession of N. epean, Logan has found a similar 
beach at 410 feet. “On the west, the highest terrace observed by the U. 
8. Geologists on the south side of Lake Ontario, appears to correspond 
With this sea level, and the gravel and sands containing elephantine re- 
, ear Hamilton, may have been washed into its western extremity 
Fae neighboring land.” Marine shells have not yet been found west 
: ngs 
t=] . 
Among the shells, Leda Portlandica and Astarte Laurentiana belong 
to the Leda clay, and are suspected to be extinct, the first, if recent, is 
stated to be the Z. truncata, and the other the A. sulcata, All the de- 
Posits overlie the inferior or “unmodified drift. eae 
This valuable paper is accompanied by two plates, containing figures 
of Several of the species noticed. 
Ne 
Upper part of the Upper Silurian, and the Oriskany Sandstone, generally 
Tegarded as Dereitian: The watvor remarks that the subdivisions of the 
e to blend intimately. But 
ups, “is fully justified by their 
rk.” 
ler n the southwest, the Oriskany sandstone contains many Crinoids simi- 
1 genera to those of the Lower Helderberg limestones. Among the 
