232 Reports and Proceedings — 



marking on the vast antiquity of many of the family types of this 

 class of the animal kingdom, and calling attention to the fact that 

 the fossil species, even from the very oldest rocks, had, with very 

 few exceptions, been referred to existing orders, the author observed 

 that it was evident that the geological record was not nearly old 

 enough or perfect enough to afford much direct evidence in support 

 of the theory of the evolution of the existing orders of insects from 

 inferior organisms. The best evidence afforded by Paleontology in 

 support of this theory seemed to him to be, that some of the species 

 from the older rocks were synthetic, combining essential characters 

 of two or more orders, and that it was probable, therefore, that 

 if insects should be detected in still older rocks, they might be found 

 to depart still further from existing types. 



Attention was then called to the antiquity of many of the existing 

 genera, and the very small amount of change, as compared with 

 that of some other classes of the animal kingdom, which had taken 

 place in many of them during the geological record. 



Mr. Goss then referred to the dates of the apparition of the 

 various orders of insects on the geological horizon. It appeared 

 that the extinct order Palcsodictyoptera and the Neuroptera were the 

 oldest orders ; that they were followed by the Orthoptera, and that 

 those orders included, with three or four exceptions, all the Insecta 

 of the Palaeozoic period, towards the close of which the Coleoptera 

 and Herniptera appeared. Early in the Mesozoic period the two 

 last-named orders began to be abundant and widely distributed, and 

 somewhat later were followed by the Diptera and certain families of 

 the Hymenoptera, and that towards the close of this period other 

 families of the Hymenoptera, including the bees, appeared ; and 

 about the same time, or early in the Tertiary age, succeeded the 

 Lepidoptera. 



Attention was then called to the important deductions which might 

 be drawn from a study of fossil insects, as to the probable state of 

 the vegetation prevailing during the period of their existence. The 

 author also observed that a comparison of European fossil species 

 with those now existing in Europe, furnished satisfactory evidence 

 of the fact that the temperature of the Continent had undergone 

 many changes, and that the size of the species, the distribution of 

 genera, and the numerical relations existing between various groups 

 indicated the former prevalence of warmer climates than those now 

 existing- in the same latitudes. 



Geological Society op London. — I. — March 12, 1879. — Henry 

 Clifton Sorby, Esq., F.E.S., President, in the Chair. — The following 

 communications were read : — 



1. "On Perlitic and Spherulitic Structures in the Lavas of the 

 Glyder Fawr, North Wales." By Frank Rutley, Esq., F.G.S. 



The rock, to the eye and under the microscope, has all the appear- 

 ance of a felstone, but in the latter also exhibits perlitic structui*e 

 as clearly as one of the Saxony perlites. Some of the other felstones 

 of the Glyder Fawr show numerous spherulites. These felstones 

 have been determined by the Survey to be lavas of Bala age. 



