Hunt., 140 [February 5, 
swept away, now forms the floor of Massachusetts Bay somewhere to 
the northward of Cape Cod. 
It is interesting to compare this evidence of submarine Tertiary 
deposits in this latitude with that noted by Prof. Verrill, in the 
American Journal of Science for October last, as obtained from 
George’s Bank and Grand Bank. The rock from the banks is sim- 
ilar to that from the Cape, though usually darker colored, being more 
argillaceous; but the widest difference is with the fossils, which ap- 
pear to show little agreement, while, according to Prof. Verrill, a large 
proportion of those from the banks are recent species. It will be ob- 
served, too, that the evidence of pre-glacial age is less conclusive in 
the case of the material dredged on the banks, than for that collected 
on the Cape. 
Dr. T. Sterry Hunt made a communication on the pre- 
Cambrian rocks of the British Islands. 
Dr. Hunt described his observations made in the summer and 
autumn of 1878 among these rocks in Carnarvon and Pembroke 
shires, Anglesea, Argyleshire and elsewhere in Scotland, and also in 
the north and the south-east of Ireland. He had farther examined, 
in company with Profs. Gosselet and Renard, the rocks of the Ar- 
dennes along the valley of the Meuse. In Wales he had the company 
and guidance of Dr. Henry Hicks. Dr. Hunt insisted on the com- 
plete parallelism presented both in stratigraphical succession and 
lithological characters (Dimetian) between these pre-Cambrian rocks 
— particularly in Wales, where they ale best displayed —and the 
pre-Cambrian rocks of North America. The most ancient rocks 
there, provisionally named Dimetian by Hicks, and chiefly gneisses, 
the speaker regarded as Laurentian. The quartziferous porphyries, 
at first united with the above, but now separated by Hicks, with 
the name of Arvonian, are the great orthophyre or petrosilex series, 
which he has described in various parts of North America as lying 
at the base of the Huronian. These, in Wales, appear separated 
by a stratigraphical break from the Pebidian rocks of Hicks, which 
are Huronian and, as displayed in Anglesea, had been by the 
speaker, many years since, referred to the Huronian series. They 
are also well seen in Argyleshire and in the north of Ireland on Loch 
Foyle. The Dublin and Wicklow hills of Ireland he regarded as 
Montalban, of which they have all the characters. 
The crystalline rocks of the Ardennes have also many of the 
characteristics of the Huronian series, but the speaker regarded it 
