354 Transactions. — Geology. 



to the south and west. The principal shock took place at 

 Imin. 20sec. past 8 a.m., or thereabouts, at a depth of 5 

 miles approximately. The velocity of propagation was 4,378ft. 

 per second ; the intensity of the shock, measured by the 

 velocity of the earth-particle, about 2ft. per second, or rather 

 more than viii. on the Eossi-Forel scale. 



Theory suggested. — The principal shock was preceded by 

 others at a much greater depth, and we may, if we please, 

 imagine a succession of rock-falls (or slidings or crushings) to 

 have taken place in the interior of that portion of the earth's 

 crust underneath the epicentric area K, P, E3, E.^. 



Art. XXXVIII. — On a Neio Plesiosaur from the WaqMra 



Biver. 



By Captain F. W. Hutton, F.E.S., Curator of the Canter- 

 bury Museum. 



\_Read before the Philosoiyliical Institute of Canterhury, 1st November, 



1893.] 



Plate XLII. 



There is in the Canterbury Museum a remarkably fine speci- 

 men of a sauropterygian, which was collected by Mr. A. 

 McKay in June, 1872,='' from the Cretaceous rocks of Bobby's 

 Creek, Waipara. It is mentioned by Sir James Hector in his 

 descriptions of the fossil reptiles of New Zealand in the Wel- 

 lington Museum, but no description or figure of the present 

 specimen has as yet been published. 



The skeleton is imbedded in a hard, grey, argillo-calcareous 

 concretion, like all the others from the same locality. This 

 portion of the concretion is nearly 6ft. long, and has been split 

 longitudinally, showing the ventral aspect of the animal. 

 Originally it was in several pieces, but they have been placed 

 together and set in plaster. As at present seen, the head and 

 neck are absent. The pectoral arch is represented by the 

 coracoids — that of the right side being nearly perfect — and a 

 fragment of the right scapula. The proximal half of the right 

 humerus is also seen. Between the coracoids, and stretching 

 out behind them, is a series of eleven dorso-lumbar vertebras 

 with only their haemal surfaces exposed. On either side, lying 

 almost in their original positions, are some abdominal ribs — 

 eight on the right and ten on the left side — four of which on 



* Geol. Canterbury and Westland, p. 169. 



