266 Ww. A. E. USSHER ON THE TRIASSIC 
Orthis Beaumontii, Vern. Encrinites. 
striatula, Schloth. Pradoecrinus Baylii, Vern. 
—— orbicularis, Vern. Tentaculites, sp. 
Gervillii, Barr. Caryophyllites, sp. 
—— Trigeri, Vern. Heliolites interstincta, M.-Hdw. 
—— hipparionyx, Schn. Alveolites, sp. 
eifelensis, Vern. Fayosites Goldfussi, D’ Orb. 
Monieri, Row. polymorphus, Goldf. 
Chonetes Boulangeri, Row. Calamopozya, sp. 
Rhynchonella, sp. Cyathophyllum celticum, D’ Ord. 
Strophomena, sp. Bouchardi, M.-Edw. 
Productus, sp. —— cexspitosum, Goldf. 
Atrypa, sp. turbinatum, Gold. 
Leptzna Murchisoni, Vern. Madrepora, sp. 
—— subplana, Vern. Aulopora cucullina, Mich. 
laticosta, Conrad. Retepora, sp. 
—— Sedegwickii, Vern. Fenestella, sp. 
— Phillipsii, Barr. Pleurodictyum problematicum, Goldf. 
depressa, Sow. (with round calices). 
Bouei, Barr. -—— (with sharp serpuliform calices). 
Calceola (sandalina). —— constantinopolitanum, om. 
Pentremites. 
Carboniferous. 
The representative of the Carboniferous Limestone occurs in a 
small space, not five miles in length by about two thirds of a mile in 
breadth, on the south-west coast, at nearly twenty miles distance 
from the unproductive Coal-measure strata of the little basins of 
Le Plessis and Littry, bounding the Triassic districts on the south”. 
With them my brief notice of the Norman Paleozoic rocks closes. 
Returning to our own side of the Channel, we find the Cornish 
peninsula composed of a granitic backbone, represented superficially 
by four principal masses, surrounded, except in the case of the Lands- 
End mass, on all sides by Devonian rocks more or less metamor- 
phosed, and constantly intersected by greenstones and elvans. We 
find the Lizard district mainly composed of serpentine and diallage 
rocks partially flanked by hornblendic slates ; whilst between Chapel 
Head and Nare Point, in the districts of Veryan and Gorran, a rock 
of pre-Devonian age occurs. 
Again, in South Devon we have the same granitic centre, and 
from it southwards pass from Culm-measure rocks to Devonian, locally 
intersected by numerous patches of greenstone; whilst the remark- 
able metamorphosis of the rocks forming the most southerly part of 
Devon, from Start Point to Bolt Head, seems to indicate the proxi- 
mity of extensive igneous districts now hidden beneath the sea. 
Taking both countries together, we have in their most southerly 
projections the indications of conditions approaching those exhibited 
in La Manche. Would not the area occupied by the English Channel 
be expected to furnish the transition between these extreme points ? 
Would not such a transitional area display great centres of ancient 
igneous activity—the extension of the Silurian and older formations 
* Bonissent, p. 260. 
