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appearance and gradually extend until mankind come to doubt 
whether they ever held the erroneous belief at all. I hope it may 
be so with Instinct. At present littlehasbeen done. Itis true suffi- 
cient has been done to show that the old belief was wrong, but 
much more requires to be done before the Naturalist will be satisfied 
to frame a definition of Instinct, and in this work many of us can 
help by careful experiments, and equally careful observations, with 
the certainty that in carrying them out we shall be sure to learn 
many things interesting to ourselves, and useful to our fellow 
creatures. 
WEDNESDAY, JANUARY 8ru, 1890. 
EVENING FOR SPECIMENS. 
Among the specimens exhibited were two meteorites, by 
Mr. E. A. Pankhurst (one from India and one from North 
America), and some skulls and sketetons of crocodiles from the 
Museum. With reference to these last, Mr. E. C. Crane, F.G.S., 
made the following remarks :— 
The structure of the skeleton in the living crocodile has 
undergone various modifications, possibly resulting from the great 
physical changes in the environment which have occurred in the 
earth’s history since their early ancestors, Stagonolepis and Beledon 
appeared in the upper Triassic rocks. The differentiation of this 
great reptilian tribe had advanced but slightly during that epoch. 
These Triassic crocodiles had many singular characters ; neither 
the palatine nor pterygoid bones were formed into osseous plates. 
In later forms these are prolonged into the nasal passages and 
give rise to the secondary nares. ‘Therefore, the nasal chambers 
communicate with the mouth by openings placed beneath the 
anterior part of the skull. The upper and lower parts of the 
body were encased in a close-fitting bony scutal armature. The 
pre-maxillaries of the Triassic Be/edon were very long, resembling 
those of Jchthyosaurus and the living cetacean—the dolphin. 
Both these crocodiles had the vertebree cupped at each end, and 
presented affinities of structure with the extinct lacertilia of the 
Permian and Carboniferous Rocks and the living Sphenodon of 
New Zealand. A great gap occurs at the close of the upper 
Triassic epoch. No crocodilian remains are known at present 
from lower Liassic deposits, but in the upper Lias of Whitby 
