Wood, Alan  <br/><br/>
The origin of the structure known as guilielmites 

 - 241-245p.  Illustration 
<br/><br/> Extract<br/>During the course of palaeontological work in the North Wales coalfield, shining discoidal bodies were noticed on the bedding planes of various shales. They were found to be identical with objects described as Guilielmites by Geinitz (4) in 1858. The literature concerning them is reviewed below, and a new theory of their origin is advanced. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Origin - Structure of Guilielmites <br/>Palaeontological work - Coalfield - North Wales