110 
THE GEOLOGIST. 
tions ;" — viz. to land-slips, or dislocations of rocky masses by gravitation, 
operating upon shaken country. 
All such are in directions on the surface tending towards transverse of 
shock. 
2. Earthquake shocks traverse furthest and most powerfully in the axial 
lines of mountain chains, and vice versa, by reason of the fact that in the 
former lines the rocky masses are most solid and homogeneous. 
3. Every earthquake emanates from a centre, which, is practically a 
point or line, or small area or surface ; and the waves of pulse, necessarily, 
are propagated in all directions outwards from such centre of impulse, 
therefore in opposite directions. 
We should suggest to our correspondent to study Mr. E. Mallet's papers 
on, 1. " The Dynamics of Earthquakes," Trans. Roy. Ii'isli Acad. 2. The 
article "Earthquake Observations," by the same author, in the 'Admi- 
ralty Manual,' 3. Mr. Mallet's first and subsequent reports on "The 
Facts of Earthquakes," Trans. Brit. Association; 
Eaethquake-shocks were felt at Cosenza (Calabria Citerior) on the 14th 
October, and at Eavenna on the 16th October last. On the 29th, a water- 
spout passed over Rome, causing much damage; the day after there oc- 
curred a violent tempest, and the magnetic instruments were greatly agi- 
tated. M. Alexis Perrey, Professor at Dijon, who for many years has fur- 
nished an annual statement of the shocks experienced by our globe, has sent 
to the Royal Academy of Belgium, a new " Note sur les tremblements 
de terre en 1859." 
Plesiosaueus in Chile. — A caudal vertebra of Plesiosaurus Chilensis 
has been transmitted to me for identification b}'- W. Bollaert, Esq.,F.R.G.S., 
from San Vicente, near Talcahuano, in the neighbourhood of Concepcion, 
Chile. This species was founded by Gay (Historia fisica y politica de 
Chile), on various vertebral bones, which were found at the small island of 
Quiriquina, off Cape Talcahuano, in the Bay of Concepcion. The vertebra 
from San Vicente appears to present no specific difference from the Ple- 
siosaurus Chilensis of Gay. A fragment of paddle-bone was found in the 
same locality. — Charles Caeter Blake. 
Sauroid Remains. — Professor Agassiz, in a letter to Dr. Silliman,* 
describes some new Sauroid remains of very great interest, discovered by 
Mr. O. C. Marsh, a student of Yale College, from the coal-formation of 
South Joggins. These are two vertebrae, which have excited Professor 
Agassiz's interest in the highest degree. He says, " I have never seen in 
the body of a vertebra such characters combined as are here exhibited. 
At first sight thej might be mistaken for ordinary Ichthyosaurus vertebrae ; 
but a closer examination soon shows a singular notch in the body of the 
vertebra itself, such as J have never seen in reptiles, though the character 
is common in fishes ; we have here undoubtedly a nearer approximation to 
a synthesis between fish and reptile than has yet been seen. . . . The disco- 
very of the Ichthyosauri was not more important than that of these verte- 
brae ; but what would be the knowledge of their existence without the ex- 
tensive comparisons to which it has led? Now these vertebrae ought to be 
carefully compared with the vetebra? of bony fishes, with those of sauroid 
fishes, of selachians^ of batrachians, of the oolitic crocodilians, of the 
newer crocodilians, of the ichtliyosaurians, and of the plesiosaurians, and 
all their points of resemblance, and difference stated ; because I do not be- 
lieve there is a vertebra known thus far, in w hich are combined features of 
so many vertebrae in which these features appear separately as character- 
istic of their type." 
* Pubhshed in the 'American Journal of Science and Art.' January, 1862. 
