Reports & Proceedings — Geologists Association. 189 



evolved from that Order. At the beginning of the Permian the 

 Stenocephalia gave rise to the reptiles which were able to survive 

 more completely arid conditions and were adapted to an entirely 

 terrestrial life. Reference at as made to Broom's theory that the 

 evolution of mammals from reptiles was rendered possible when the 

 Theromorphs developed limbs which enabled them to carry the body 

 off the ground. The aridity of climate during Permian times served 

 as an incentive to speed, and the extensive glaciation, which 

 supervened during that period in the Southern hemisphere, favoured 

 the acquisition of warm blood and of heat-retentive clothing. In 

 their anatomical features the Theriodonts of the Permian and Triassic 

 bridge the gap between reptiles and mammals. This was illustrated 

 by a description of the origin of the paired occipital condyles of the 

 mammal from the tripartite single condyle of Theromorphs, by the 

 gradual reduction of the bony elements of each half of the lower jaw 

 in these reptiles, by their heterodont dentition, by the structure of the 

 shoulder and hip girdles and other features. 



2. Specimens of native gold from Rhodesia were exhibited by 

 Dr. M'Lintock. 



IV. — Geologists' Association 



The annual general meeting of the Geologists' Association was 

 held at University College, Gower Street, W.C. 1, on February 1, 

 1919, when the following lecture was delivered : — 



"The Nimrud Crater in Turkish Armenia." By Felix Oswald, 

 D.Sc, F.G.S. 



The Nimrud volcano, situated on the west coast of Lake Yan in 

 Turkish Armenia, has a perfect crater nearly five miles in diameter. 

 The precipices of the crater-wall rise two thousand feet abruptly from 

 a deep lake which fills half the area of the crater. The lecturer 

 described the external and internal features of this great volcano, 

 which he visited and surveyed some years ago, and he gave a 

 summary of its geological history down to its last eruption in 1441. 



The lecture was illustrated by lantern-slides, photographs and 

 drawings. 



March 1, 1919. 



" Some Suggestions on the Flaking and Evolution of Flint 

 Implements." By S. Hazzledine Warren, F.G.S. 



The paper dealt with the following points: — 



Characteristics of the fracture of flint under internal molecular 

 strain, flexion, tension, compression, etc. The planes of least 

 resistance — what they are and what they mean. The designed flake 

 and the accidental chip. Normal flaking at about 75° tending to 

 cuneiform flakes. High angle aud low angle edge-flaking tending to 

 incurved flakes. The Levallois-Pressigny method. Suggested 

 evolution of the Neolithic axe and double axe from special forms of 

 palseoliths. Possible development of the Neolithic arrow-point, 

 scraper, sickle-knife and certain other implements from the Mousterian 

 racloir along divergent lines of evolution. The importance of wood 

 and bone for implement making in past human industries. 



