92 Transactions of the 



with objects of latent beauty, that perhaps eternity alone 

 will open up and develope sufficient opportunities to enable 

 us to survey, admire, and appreciate them all.' 



The Chairman made a few remarks upon the invaluable 

 assistance rendered by the microscope to the study of insects, 

 and then called upon H. Wills to read his Paper on 



THE LIAS OF WHITBY. 



The liassie formation consists of marine clays, shales, and 

 limestones, abounding in shells, crinoidea, crustaceans, fishes, 

 and extinct reptiles ; with fluvio-marine beds, containing 

 insects, minute crustaceans, lignite, trunks and leaves of 

 coniferous trees, and cycadeous plants. 



It is the lowermost group of the Oolitic system, amounting 

 to many thousand feet in thickness, the principal litho- 

 logical features being the uniform aspect and distinctly strati- 

 fied character of its limestones and argillaceous layers ; and 

 with most constant subdivisions. 



Geographical position. — The lias from the extreme north of 

 the Yorkshire coast passes through Whitby to the south, 

 and stretches through the rest of Yorkshire and Lincolnshire, 

 continuing through Nottingham, Warwick, and Gloucester, 

 and presents a remarkable regularity in breadth to within a 

 few miles south of Gloucester, where it disperses. 



Whitby is the centre of the great lias formation, which 

 reaches in a frequently interrupted belt to the Tees, but to 

 the south without any break as far as Eobin Hood's Bay. 

 The proximity of the Oolite is also noticeable, the very 

 crevices in some of the lias rocks bemg filled up with it. 

 The Lower Lias forms the lowest and most precipitous part, 

 and is made up of dark blue slaty clay. The cliff consists of 

 the Upper Lias, being friable and of a grey colour. They 

 are both full of fossils and are exceedingly interesting, and 

 the whole coast is rich in great Saurian remains. Prom the 

 Lower Lias alum used to be extracted, whence it is called 

 alum shale, and even now traces of it can be found. Some 

 way along the beach or scar is the lighthouse, beyond which 

 a very valuable fossil plant, caUed Equisetum or Horsetail, 

 used to be obtained, found in an upright position as it had 

 grown and been buried in the sand. 



Reptiles. — The most striking of all the organic remains 

 are the fossils of huge Enaliosaurs, or marine lizards, both for 

 number, size, and structure. Of these there are two genera 

 most remarkable — the Ichthyosaiu-us and the Plesiosaurus. 



