110 



THE GEOLOGIST. 



tions ;" — viz. to land-slips, or dislocations of rocky masses by gravitation, 

 operating upon shaken country. 



All suck 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. 1?.. Mallet's papers 

 on, 1. " The Dynamics of Earthquakes," Trans. lioy. Irish 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. 



Earthquake-shocks were felt at Cosenza (Calabria Citerior) on the l-lth 

 October, and at Eavennaon the 16th October last. On the 29th, a water- 

 spout passed over Eome, causing much damage ; the day after tbere 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 Eo3^al Academy of Belgium, a new " I^ote sur les tremblements 

 de terre en 1859," 



Plesiosatjeus in Chile. — A caudal vertebra of PZe5?'o5(7zirM5 CMlensis 

 has been transmitted tome for identification by W. Bollaert, Esq.,F.E.G.S., 

 from San Vicente, near Talcahuano, m 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, otF Cape Talcahuano, in the Bay of Concepcion. The vertebra 

 from San Vicente appears to present no specific difl^erence from the Tie- 

 siosaiirus Chilensis of Gay. A fragment of paddle-bone was found in the 

 same locality ; — Charles Carter Blake. 



Sauroid Eemains. — 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 vertebra, 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 they might be mistaken for ordinary Ichthj^osaurus vertebrae ; 

 but a closer examination soon shows a singular notch in the body of the 

 vertebra itself, such as I have never seen in reptiles, though the character 

 is common in fishes ; we have here undoubtedly a nearer approximation to 

 a syndiesis heiween f sh and reptile than has yet been seen; . . . The disco- 

 very of the Iclithyosauri w as not more important than that of these verte- 

 bra^ ; but what would be the knowledge of their existence without the ex- 

 tensive comparisons to which it has led ? Now these vertebrfe ought to be 

 carefully compared with the vetebra of bony fishes, with those of sauroid 

 fish(>s, of selachians,^ of batrachiaus, of the oolitic crocodilians, of the 

 newer crocodilians, of tlie idithyosaurians, and of the plesiosaurians, and 

 all their points of reserablamv . a"ud diflference stated ; because I do not be- 

 lieve there is a vertebra kuo\\ n thus far, in which are combined features of 

 so nniny vertebrfe in which these features appear separately as character- 

 istic of their type." 



* I'ublislKil ill \\w ' Amorioan Journal of Science aud Art.' Jaimarv, 1862. 



