156 TRANSACTIONS, NATURAL HISTORY SOCIETY OF GLASGOW. 



mica. The organic remains consisted of one small 

 fish-scale, a few crinoid remains, six spicules of 

 Hyalostelia gracilis, H., a spicule of a glass-rod 

 sponge, two small fish teeth, one conodont, and 

 numerous small pearls varying in colour from opa- 

 lescent milky-white to a rich amber. The limestone 

 contains abundance of the large Brachiopod Penta- 

 merus Knightii. 



41. Railway - cutting near Stock Say Castle, 

 Shropshire. —Yellowish shale, with minute scales 

 of white mica, some brown mica, a few well-rounded 

 quartz-grains, some prismatic, opaque, and transpa- 

 rent calcite, a few spicules of Hyalostelia gracilis, H., 

 and one small fish-scale. 



42. Quarry in Upper Silurian Limestone, two 

 miles East from Craven Arms Railway Station. 

 — This gathering was from rotted cavities in the 

 limestone, and contained abundant spicules of 

 Astractosella sihiriensis and Hyalostelia gracilis, de- 

 scribed by Dr. Hinde in Vol. XL. of the Palseonto- 

 graphical Society's Publications. Conodonts were 

 common. 



43. Brow, near Norbury, Shropshire. — This was 

 a sample of a brownish-rusty colour from the 

 rotted cavities in the Aymestry Limestone. The 

 bulk of the washed material consisted of rather 

 angular siliceous particles averaging about ,J^ of an 

 inch, a few well-rounded quartz-grains up to ^ of 

 an inch, and a few fragments of talc or clay slate. 

 It is a noteworthy fact that in the shales or lime- 

 stones no rounded particles of a smaller size than 

 about i^ of an inch have been detected, and up to 

 ^^jf of an inch they are by no means well-rounded. 

 Apparently, when a smaller particle than this is 

 knocked off from the parent mass, its minute size 

 causes its floating power in water to become so 

 great that it ceases to be capable of rolling along 

 the bottom and having its edges worn off, and 

 the slightest movement of the water causes it to 

 float. 



