298 



THE GEOLOGIST. 



that possibly the local reconstruction of the Chalk may have been contempo- 

 raneous with the formation of the Thanet Sands further to the east. 



5 " On some of the Higher Crustacea from the British Coal-measures." 

 By J. W. Salter, Esq., F.G.S. 



In this paper were described, (1) a new Macrurous Crustacean, under the 

 name of Anthrapalcemon Grossarti, from the slaty band of the black band iron- 

 stone of the coal-measures, Goodhock Hill, Shotts, Lanarkshire. (2) The 

 Macrurous Crustacean of which an imperfect specimen was figured in Mr. 

 Prestwich's memoir on the Coalbrook Dale Coal-field (plate 41, fig. 9, Apus 

 dubius) : this is referred to a subgenus (Paleeocarabus) of the genus Anthra- 

 palamon; and another specimen from Kidgeacre Colliery was referred to. 

 (3) A specimen from the Carboniferous Limestone of Derbyshire. (4) A small 

 Crustacean, from the Mountain-limestone of Fifeshire, figured and described 

 by the author in the 'Transactions of the Roval Society of Edinburgh,' 

 vol. xxii. p. 394, as Uronectes socialis, but now regarded by him as belonging 

 to the Macrura. 



Royal Institution. — March 22, 1861. 



"On the Origin of the Parallel Roads of Lochaber (Glen Roy)." By Pro- 

 fessor H. D. Rogers, E.R.S., E.G.S., &c. 



The speaker prefaced his account of these curious features in the scenery of 

 Lochaber, by stating that he was induced to recall attention to them from 

 having, during four recent visits to the ground, discovered certain phenomena 

 not hitherto noticed or theoretically considered by any of the able and dis- 

 tinguished observers who have preceded him. Though nearly all the more 

 prominent peculiar characters of the scene have been very skilfully described 

 and discussed by Dr. MacCulloch, Sir Thomas Dick Lauder, Charles Darwin, 

 Esq., David Milne Home, Esq., Professor Agassiz, Sir George S. Mackenzie, 

 Robert Chambers, Esq., and others, Professor Rogers has been led by a careful 

 study of the structure of the so-called Parallel Roads, and a perusal of the 

 views of those eminent geologists, to reject all the hypotheses thus far offered 

 in explanation of the terraces as inadequate, and to recognize in the facts about 

 to be developed, a key to a solution of the problem of their origin which he 

 thinks may prove satisfactory. 



The geographical area of the parallel roads may be defined as embraced be- 

 tween Loch Laggan and Loch Lochy, east of the Great Caledonian Valley. 

 They are chiefly restricted indeed to Glen Spean, Glen Roy, and two or three 

 immediately adjacent smaller glens. One belt of them ranges from near Spean 

 Bridge up the Spean Valley, to beyond the head of Loch Laggan ; another up 

 Glen Roy to the water-sheds at its very head, and a third through Glen Gluoi 

 to its head. 



The " Roads" or Shelves themselves are of various heights above the sea, 

 the lowest of the three conspicuous ones in Glen Roy having an elevation of 

 about 850 feet, the middle one a height of about 1060 feet, and the highest a 

 level of nearly 1140 feet. Other much fainter, still more elevated shelves are 

 discernible in Glen Gluoi, but all hitherto seen lie below a horizon of 1500 feet 

 above the ocean. These Parallel Roads, as they are called, are apparently level, 

 and therefore parallel, but further instrumental measurements are necessary 

 before the question of their absolute horizontality can be regarded as satis- 

 factorily settled. 



They constitute a most impressive feature in the scenery of the lonely, 

 treeless glens containing them. Winding into all the recesses and round 

 the shoulders of the mountains which they imprint, they present at first 

 view a striking likeness to a succession of raised beaches deserted by their 

 waters. 



