Geology and Mineralogy. 317 



undoubtedly brachiopods of the pleuropygian order, but with 

 characters intermediate between Lingulidiw and Discinidce. He 

 reminded the section that he had years before assigned the 

 -Baraboo quartzite to the Lower Silurian on lithological grounds, 

 though Professor Irving had subsequently attempted to invalidate 

 •the reference. E. "W. Claypole thought the objects exhibited 

 were undoubtedly organic and coincided as to the affinities of the 

 shells. 



(10.) A. Winchell. On Coenostroma and Idiostroraa and the 

 comprehensive character of Stromatoporoids. Enumerated the 

 structural characters found in the group, and traced the mor- 

 phology of each structure separately, showing on what grounds 

 generic distinctions had been based. He then indicated the 

 assemblages of characters which distinguish Coenostroma and 

 Idiostroma from other genera, and gives them validity. He 

 finally pointed out the fact that the Stromatoporoids possess a 

 very wide range of affinities : with Sponges, in external aspect, 

 curdled tissue, water canals and oscula, though none of these 

 characters are present in all ; witli Foraminifera, in their laminae 

 and interspaces ; in their radial, branching canals, seen in Eozoon, 

 and in the concentric layers, interspaces and curdled structures of 

 foraminiferal ParTceria y with Anthozoa, in their laminae (com- 

 pared with Meliolitidce and some Favositidoz), their radial struc- 

 tures, their individuation (incipient in Coenostroma, completed in 

 Idiostroma), and the (by some) supposed tabulae of Caunopora • 

 with Hydrozoa, in the resemblances of Hydractinia and more 

 strikingly, Ldbechia, which may be regarded really a Stromato- 

 poroid; with Polyzoa, in the tubes and (supposed) tabulae of 

 Caunopora, and some further resemblances of Eschara nobilis. 

 It is vain, therefore, to seek to place Stromatoporoids within the 

 bounds of any recognized class-type. The author exhibited 

 numerous specimens, thin sections and photographs illustrating 

 generic distinctions, and circulated a printed synopsis of Stroma- 

 toporoids. 



For a full list of the geological papers presented to the Associa- 

 tion see page 324. 



2. Can underground heat be utilized? — J. Starkie Gardner 

 has an article on this subject in the Geological Magazine for 

 September. The author concludes from the increase of heat 

 downward, from metamorphism, from volcanoes, and from the 

 earth's up and down movements, that there is abundant reason 

 for believing that the earth has a thin crust. The movements 

 would be physically impossible in an earth solid throughout. If 

 -the principal mass is kept solid at a temperature beyond the 

 fusing point of rock through the pressure of the external envelope, 

 "the pressure must become relaxed as the surface is neared, and 

 at a certain point the rock must obey its impulse and melt," and 

 thus make a layer in a state of fusion. The movements of the 

 crust are more compatible with a crust of ten miles thickness than 

 with one of fifty miles. "The deepest artesian well in the world 



