Geology and Mineralogy. 69 



ave believed that many geologists give much less credit to 

 shrinkage fissures" than thev are entitled to. This cause is 

 dvocated in my "Valleys and their relations to Fissures, Frac- 

 ures and Faults," especially in chapter ii; also in different 

 lemoirs to accompany the maps of the geological survey of 

 reland. In Connemara or West Galway many of the narrow 

 eep gorges I believe to be due nearly solely to the drying ami 

 ontraction of the rocks after they became dry land; while in 

 ■ ■■•- in the county of Clare there are, under the basal 

 Carboniferous conglomerate sandstone and shales, peculiar siliceous 

 r calcareous rocks that send down dykes into the underlying 

 'ambro-Silurian rocks; and these dykes and other intrusions, as 

 tared in the memoirs. 1 helieve to have filled " shrinkage fissures" 1 

 i the older rocks. Similar! v. in the counties Mavo and Galway, 

 lie basal bed of the Silurians (or Lower Old Red Sandstone) 

 it rudes downward, tilling fissures in the metamorphosed Cambro- 

 ilurians. In the coals of the Coal-measures many of the 

 troubles" or "horses" were filled from above, and anciently 

 ere 'shrinkage fissures- ;"' while in other places it appears to me 

 ntny dykes of "fault-rock" are the filling in from above of 

 shrinkage fissures." 



4. Aiitericttn (,, ulnipral Sm-n-ty. — The proposal to organize an 

 Unerican Geological Society was brought up at the last meeting 

 i Association, and a committee was appointed to 



■ the advisability of it and report at 



usts of N. H. Winched of Mil 



lesota, John H. Proctor of Frankfort. Kentucky, II. 

 iams of Ithaca, X. Y., John ( 

 low of Columbia, .Missouri, Wn 



Collett 



[entucky, H. S. 

 lianapolis, G. C. 



ati, Ohio. The chief objectu 

 al, was that the American Ass. 

 ial parts a geological associati 

 eded by geologists in case the 

 leetings and no permanent \ 

 appears to be good. The < 



promote greatly the progress of the science it it 

 ai and money to sustain it. .Money would be 

 order that all memoirs offered might be fully 



Of tht>. Fowl Fn,',tn,tnif-m nf the ColUcUOH Of 



