FOSSIL SPONGE SPICULES 



FROM THE 



UPPER CHALK. 



FOUND IN THE INTERIOR OF A SINGLE FLINT-STONE FROM 

 HORSTEAD, NORFOLK. 



BY 



GEORGE JENNINGS HINDE. F. G. s. 



The sponge spicules herein described were obtained from 

 the material contained in the interior of a nodular flint, about 

 one foot in diameter, which had been imbedded in the strata 

 of the Upper Chalk Formation at Horstead, near Norwich. - 

 In the Chalk pits or quarries in this neighbourhood not only 

 are the nodular flints arranged in horizontal layers coinciding 

 wich the stratification of the Chalk but they are also disposed 

 in vertical layers, and the nodules thus arranged vertically are 

 often of much larger size as well as different in form to those 

 of the horizontal beds. Many of these larger flints are more 

 or less cylindrical and either hollow throughout like a tube or 

 with a deep cup-shaped depression at one end which has 

 led them to be compared with the large horny sponges called 

 Neptune's cups, though there is no evidence to show that they 

 are more allied to these sponges, beyond a rude resemblance 

 in outer form, than the ordinary shapeless nodules of the hori- 

 zontal layers. On account of their peculiar form, these cy- 

 lindrical, partly hollow masses of flint have been termed pot- 

 stones or paramoudras. They have by no means a general 

 distribution in the upper chalk strata, though they are of fre- 

 quent occurrence at Horstead and are also met with in many 

 of the Chalk pits near Norwich, and they appear as well in 



