.Reviews — Edinburgh Qeological Society. 233 



surface of tho alluvium, ho thinks, is against the probability of its 

 having Leon deposited by the Poorna under existing conditions. 



Laterito occurs in several places. 



The cotton or black soil, which occurs largely in tho Poorna 

 valley, as is usual in trappean districts, has no geological peculiarity, 

 and has therefore not been treated of by Mr. Wynne. He remarks, 

 that to its development, and to the fertile nature of soils derived 

 from tho Trap, may doubtless bo traced tho name vv^hich this country 

 has obtained as a cotton-producing district. — H. B. W. 



III. — Transactions of the Euinburgu Geological Society. 

 Vol. I. Part III. 8vo. 1870. 



THE papers contained in this Part are those read before the 

 Society between November, 1868, and June, 1869 — and with 

 them is completed the first volume of the Society's Transactions. 

 The whole is well pi'inted, and illustrated with many plates and 

 wood-cuts. Most of the papers have been noticed previously in the 

 Geological Magazine, witla the exception, of four read on the 6th 

 of May, 1869. 



1. Note on the occurrence of Actinocrinus pulcher in the Uj)per 

 Silurian Flag of Denbighshire. By D. W. Eoberts, M.B., etc. The 

 author records a new locality (Galt-y-celyn, Derwen) for this rare 

 Encrinite, which hitherto had only been found in two places in 

 North Wales. 



2. On two Eiver Channels buried under Drift, belonging to a 

 period when the land stood several hundred feet higher than at 

 present. By James Croll. The author described an ancient river 

 channel buried under drift, extending from Kilsyth to Grangemouth, 

 which has been discovered through means of borings for minerals. 

 The journals of these borings were collected for the purpose of 

 ascertaining the depth and character of the surface deposits of the 

 country ; and it was while examining these that the incidental 

 discovery was made of a deep preglacial, or perhaps interglacial, 

 trough or hollow, extending from the Clyde, above Bowling, by 

 Kilsyth, to the Firth of Forth, near Grangemouth. It was clear 

 that this hollow was not due to a fault, but to denudation, as the 

 strata which it cuts through were found to be intact and unbroken 

 beneath, proving that it had been cut out of the solid rock. The 

 author thinks that the western half of this great hollow, extending 

 from the watershed at Kilsyth to the Clyde, is also an old river 

 channel, probably the ancient bed of the Kelvin. He concluded 

 that this hollow had been cut out by running water in the form of 

 rivers, when the land stood higher than now. These rivers, starting 

 from the present watershed of the district near Kilsyth, would run, 

 the one westward, flowing along the valley of the Kelvin, into the 

 Clyde near Bowling, and the other eastward, along the present 

 course of the Bonny Water, till it entered the Firth of Forth near 

 Grangemouth. The geological state of this ancient river channel is 

 shown by the deepest bore at Grangemouth to be either just before 



