Geological Society. 1 4-9 



2. That as far as our present knowledge extends, all the true re- 

 sins are capable of being represented by irrational formula?, in which 

 C 40 is a constant quantity. 



3. That the analyses contained in the present paper render ne- 

 cessary a slight modification in the general formulae previously an- 

 nounced. The formula for the group of which colophony is the 

 type, being C 40 H 32 + x Oy ; and that for the group of which gam- 

 boge or dragon's blood is the type, being C 40 H J4 + x Oy. 



The author announces a further continuation of these researches, 

 in which the constitution of other resins will be given, and the re- 

 lations of the resins to certain chemical reagents will be explained 

 and illustrated. 



The Society then adjourned over the Easter Recess, to meet again 

 on the 30th of April. 



GEOLOGICAL SOCIETY. 

 [Continued from p. 74 of the present volume.] 



Dec. 18, 1839. — A paper was first read, entitled "Description 

 of the fossil remains of a mammal, a bird, and a serpent, from the 

 London clay," by Richard Owen, Esq., F.R.S., F.G.S. 



The author commences by observing, that only a few months had 

 elapsed since the highest organic animal remains known to exist in 

 the London clay were those of reptiles and fishes ; and that the 

 danger of founding conclusions in Palaeontology from negative 

 evidence was perhaps never more strikingly illustrated than by the 

 fact, that the first scientifically determined relic of a warm-blooded 

 animal from that formation proved to belong to the highest order of 

 that class, if man be excepted ; and that besides those quadruma- 

 nous remains, there have since been discovered in the London clay 

 underlying the coralline crag, near Kyson, in Suffolk, teeth of cheiro- 

 ptera, and of a species probably belonging to the marsupial order*. 



Mr. Owen then proceeds to describe the fossils, the immediate 

 objects of the communication. 



1. The portion of the mammal was discovered by Mr. Richardson 

 in the cliffs of Studd Hill, near Heme Bay, and belongs to a new 

 and extinct genus of Paclvydermata. It consists of a small mutilated 

 cranium about the size of that of a hare, containing the molar teeth 

 of the upper jaw nearly perfect, and the sockets of the canines. The 

 molars are seven in number on each side, and resemble more nearly 

 those of the Chseropotamus than of any other known genus of 

 existing or extinct mammalia. They present three distinct modifi- 

 cations of the grinding surface, and increase in complexity from 

 before backwards. The first and second spurious molars have simple 

 sub- compressed crowns, surmounted by a single median conical cusp, 

 with a small anterior and posterior tubercle at the outer side, and a 

 ridge along the inner side of its base. They are separated by an 



* Annals of Natural History, Nov. 1839. 



