Geological Society of London. 281 



Journal of the Geological Society for 1894, two important papers 

 by Dr. Beecher have appeared, giving details as to the structure 

 and appendages of Triarthrus. 



In the present paper the author discusses in detail the more 

 recent discoveries in the light of the affinity between Apus and the 

 trilobites, and endeavours to show how the results obtained^ by 

 Dr. Beecher bear on the larger question as to the suggested origin 

 of both of these animals from a chjetopod annelid modified in 

 adaptation to a new manner of feeding. 



3 " An Experiment to Illustrate the Mode of Flow of a Viscous 

 Fluid." By Prof W. J. Sollas, D.Sc, LL.D., F.E.S., F.d.S. 



The author, recognizing that it is by a knowledge of the laws of 

 viscous flow that we must seek to extend our information concern- 

 itio- the movements of flowing ice, conducted an experiment, the 

 details of which are described in the paper, with a model of a glacier 

 composed of the modification of pitch usually known as "cobbler's 

 wax." In the model the pitch moved under its own weight over 

 the horizontal floor of a trough, which was crossed by a barrier 

 to represent an opposing mountain or the rising end of a lake. The 

 results of the experiment showed that the movement of the pitch- 

 glacier was not confined to that portion of it which rose above the 

 barrier, but extended throughout its mass, and that an upward as 

 well as forward movement took place as the barrier was approached. 

 Ilius the transport of stones by glaciers from lower to higher levels 

 was by no means an incredible phenomenon, but a necessary 

 concomitant of such simple conditions as those assumed in the 

 experiment. 



III.— May 8th, 1895.— Dr. Henry Woodward, F.K.S., President, 

 in the Chair. The following communications were read :— 



1. "The Stirling Dolerite." By Horace W. Monckton, Esq., 

 F.L.S., F.G.S. . , ^ ., 



The rock described in the paper forms a mass about eiglit miles 

 in length, with an average width of about a mile ; it is intruded 

 into the lower part of the Carboniferous Limestone series. There 

 is little doubt that the Abbey Craig rock, north of the Forth, is 

 connected with the Stirling rock ; and there is reason to think that 

 the igneous rocks of Cowden Hill and of the hills around Kilsyth 

 are outlying portions of the Stirling rock, being connected with it 

 underground. 



All these patches, as well as the main mass, are for the most part 

 composed of a more or less coarse-grained dolerite, the marginal 

 part always becoming finer-grained, whilst the actual edge has 

 apparently been a tachylyte now devitrified. 



The author gives the results of his macroscopic and microscopic 

 examination of the rocks from various parts of the mass. He 

 describes rocks from the centre, and also towards the bottom and 

 top of the main mass, including actual contact-specimens from 

 the bottom at Sauchie Craig and from the top at Saucliieburn 

 as well as contact-specimens from minor sheets ; and he inters 



