254 Geological Society. 



the forceps or otherwise, it does not itself move, but the other 

 or unpoisonecl half immediately responds to the stimulation. If S. 

 laciniata be the species of Medusa employed, this result is par- 

 ticularly well marked, from the fact that the unpoisoned half re- 

 sponds to the stimulation by performing the highly distinctive 

 spasmodic movements already described. I have also satisfied 

 myself that curare asserts its peculiar influence upon individuals 

 of the covered-eyed Medusae. In all cases overpoisoning paralyzes 

 the excitable as well as the motor system. The strength of the 

 solution I used was 1 in 2500, and in this solution the poisoned half 

 required to soak for half an hour. 



\e) If any sized portion of a contractile strip cut from the 

 gonocalyx of A, aurita be immersed in a sea-water solution of any 

 of the above-mentioned ansesthesiating substances, the contractile 

 waves in the poisoned portion of the strip are first progressively 

 slowed and finally blocked. Upon now restoring the poisoned 

 portion of the strip to normal sea- water, the contractile waves 

 again begin to pass, and eventually do so as freely as before. 



If any of the nutrient tubes which cross such a contractile strip 

 transversely be injected with a solution of any of the narcotic 

 poisons, the contractile waves become blocked at the line occupied 

 by that tube. If a discharging lithocyst be similarly injected, it 

 ceases its discharges. From the effects of chloroform and weak 

 solution of morphia, however, it recovers in the course of a night. 

 Alcohol so injected at first causes an increase in the frequency and 

 potency of the discharges, and afterwards progressive torpor. In 

 time, however, the torpidity wears away, and finally the Medusid 

 returns to its normal state. 



Geological Society. 



February 2nd, 1876. — John Evans, Esq., F.R.S., President, 

 in the Chair. 



"Evidence of a Carnivorous Reptile (C^/uoc^ra con major, Ow.) 

 about the size of a Lion, with Remarks thereon." By Prof. Owen, 

 C.B., F.R.S., F.G.S., &c. 



The specimens described by the author consist of the fore part of 

 the jaws and the left humerus of a reptile obtained from blocks of 

 Triassic (?) rock from South Africa, forwarded by the late Mr. A. G. 

 Bain, F.G.S. The upper jaw displays a pair of enormous canine 

 teeth, much resembling those of Machairodus, being of a very com- 

 pressed form, with the hinder trenchant margin minutely toothed. 

 There is no dentated border to the fore part of the crown. No teeth 

 can be detected in the alveolar border of the right ramus of the lower 

 jaw, which extends about an inch behind the upper canine. In 

 the symphysial i)arts of the lower jaw the bases of eight incisors 

 and of two canines are visible, the latter rising immediately in 

 front of the upper ones, to which they are very inferior in size, and 

 being separated by a diastema from the incisors. In this character, 



