186 
May 30, 1870. 
The PRESIDENT (PROFESSOR CAYLEY) in the Chair. 
New Fellow elected: 
F.S. Barre, M.A. Christ's College. 
Communications made to the Society: 
(1) On the Invention of the Camera Lucida by Wol- 
laston. By Professor Miuuzr, F.R.S. 
Among a collection of scientific instruments placed under 
the care of the University by Mr Elphinstone, Professor 
MILLER had found two glass prisms cemented together and a 
four-sided prism of glass, together with other combinations of 
lenses and prisms; to some of which reference was made by 
Wollaston in two or three papers in the Philosophical Trans- 
actions. Professor Miller showed how these instruments might 
be used in discovering and approaching to the regular form of 
the camera lucida. 
(2) On the Frontal Bone in the Ornithosauria; with 
additional evidence of the structure of the hand in 
Pierodactyles from the Cambridge Upper Green 
Sand. By Mr H. Ssertry, F.GS. 
The portions of the head hitherto obtained from the Cam- 
bridge Upper Green Sand are the back part and front part 
of the mouth. The specimen exhibited was part of the frontal 
bone, which showed that the Pterodactyle approached closely to 
the avian type. Mr SEELEY had for some time supposed that 
the fingers of the Pterodactyle had been misplaced, and the 
descriptions usually given and the specimens exhibited, in his 
opinion, fully confirmed that suspicion. 
