330 Scienlific Memoranda. 



A new practice of Painting : communicated to the Royal Institu- 

 lion of Great Britain. — Mr. Robertson paints in water-colours, and 

 upon paper. He uses isinglass, dissolved in hot spirits of wine, 

 between and over his colours, by which they acquire the bril- 

 liancy and force of oil; and when the picture is finished, he 

 covers it with a colourless copal varnish. The pictures, when 

 large, are covered with canvass and tin-foil. The durability and 

 steadfastness of the colours appear to be extreme. — Phil. Mag. 



Description of a 7icw Species of Ichthyosaurus. — A paper on this 

 subject by Daniel Sharpe, Esq. F. G, S. was read before the Geo- 

 logical Society of London. — This Ichthyosaurus was found in a 

 quarry of lias limestone, about four miles from Stratford-upon- 

 Avon. The whole length of the animal must probably have 

 been about seven feet; the parts of it which remain exhibit the 

 upper portions of the head from the nostrils backwards, in a very 

 crushed state, a continuous series of 52 vertebree, from the atlas 

 to the commencement of the tail, with nearly all the spinous 

 processes; one scapula, and nearly the whole of one fore paddle. 

 The teeth (by which the four species formerly described have 

 been chiefly distinguished) are entirely wanting in this indivi- 

 dual ; the author, however, considers it to be a new species, from 

 the following peculiarities of character: — 1. The length of each 

 vertebrae is uniformly three-fifths of its breadth, a proportion not 

 found to exist in any hitherto described species. 2. The paddle 

 ^is of great size, and including the humerus, must have been 

 equal to one-fifth of the length of the whole animal. In the ulna 

 or radius, (it is difficult to say which,) there is a notch on the 

 outward edge, and all the other bones of the paddle are very 

 nearly circular or oval; thus dilTering essentially from the an- 

 gular shaped phalanges of I. communis, temiirostris, and inter- 

 medius. On account of the large size of its paddle, the author 

 names this species " Ichthyosaurus grandipes." 



Proceeditigs G. Sac. of London. 



Formicological Waterloo. — On the 16th of last May, I was 

 walking in the garden before breakfast, when my attention was 

 attracted by an unusual assemblage of ants in the gravel walk ; 

 the species, I believe, was that of which liuber, in his History of 

 Ants, has given a representation, and is called by him formica 



