142 



THE GEOLOGIST. 



Errata in Mr. Du Noyer's Paper on the Giant's Causeway. — 

 Dear Sir, — Please to call attention to the following typographical errors in the 

 paper on the Causeway. Any practical geologist seeing lign. 7, p. 10, called 

 "The Whin Dyke," woidd at once perceive the error. No dyke of basalt ever 

 assumed the fi|)pea)'ance given in lign. 7 when vertical, but it might if it were 

 horizontal, mIiou, liowever, the cohimns would be more regular than those 

 shown in the figure I allude to. The peculiar character of all trap-dykes is 



a a 



Silurian Slate. Trap Dyke. Silurian Slate. 



their tendency to columnarize at right angles to their walls, or cooling surfaces ; 

 wliile what may be ieYiatdi joints of shrinking (a a) become very numerous and 

 close at the edges of the dyke. In many instances the dyke at its sides de- 

 composes into a soft brown shale. 



At p. 11 the allusion to Kgn. 7 refers to lign. 6. — Yours very truly, 

 Geo. V. Du Noyer. 



Notes or Possiliferous Localities oe the Old Eed Sandstone of 

 THE East of Scotland. — Should any amateur geologists, delighting in a 

 pedestrian excursion, relieved occasionally by a little rail and steamboat 

 travelling, be desirous of visiting the fossiliferous districts of the Old Ked 

 Sandstone of the east coast of Scotland dmlng the ensuing season for rambles, 

 I think the following remarks may be of some service in the search for speci- 

 mens. The trip, by using a little despatch, will take about five or six weeks ; 

 to go thoroughly to work, and obtain a perfect knowledge of the localities, &c., 

 would require at least five or six months. However, 1 was not able to spare 

 more tlian six weeks, and during that time 1 visited all the most important 

 places of interest to the geologist in that part of Scotland, with tolerably fine 

 weather, and without being overburdened with baggage, but possessing a very 

 useful and moderate-sized hammer (a smaU hammer is of no use in this dis- 

 trict) and a couple of stone-chisels (large and small) ; with these tools you can 

 encounter a nodule of almost any size ; but the hammer itseK will generally 

 prove suflTicicnt, unless the nodule breaks crossways. 



At the end of these rough remarks 1 have given a list of all the Old Red 

 fishes found in Scotland, with the locality of each species ; this may be useful, 

 to enable the tourist to know Mliat species are to be met with in the places he 

 visits. I liave taken each place in the order 1 visited them, commencing with 



Cromarty, the locality rendered famous by Hugli Z\Iillcr, as the first ex- 

 amined l)y liim in his researches on the Old Red Sands^tone, nearly thirty years 

 ago. Tli(n-e arc many species found here, but rarely any in a remarkably good 

 state of preservation ; the most abundant appear to be tlie Diplacantluis striatKS 

 and a Chciracanthus. Large numbers of sea-worn nodules containing the re- 

 mains of iishes may be picked up on the coast at low water, especially after 

 rough weather ; these seldom contain anything very fine. I searched nearly a 

 whole (lay with very little success; however, the next day I was more tor- 

 tunate in ])rocurhig scver;d good s])ccimens by digging some two or three feet 

 in one or two beds on the shore containing the n^exlules. These were some of 

 tile beds that Hugh Miller used to visit in liis geological rambles. It is not, 



