140 Correspondence — Fossil Beads. 



In the same volume of the Geologist (pp. 235-6) Professor T. Kupert 

 Jones points out that these bodies, so common in the gravel of Chalk 

 districts, particularly in Bedfordshire and at St. Acheul, have all 

 been, originally, derived from the Chalk in which they are ahmdanth/ 

 found, either perforated or solid, or with a more or less shallow liole 

 in their substance. They occur in the Chalk itself; on the beaches 

 under Chalk cliffs (as at Eamsgate, etc.) and in drift beds, the 

 materials of which have been furnished by the Chalk, and in the 

 decomposed chalk along the bottom slopes of the North and Soutli 

 Downs. 



" The concavity of the typical variety {Porosphcera glohularis) 

 becomes in many of the globular forms a small cavity, a hole, or 

 even a neat cylindrical perforation. The roundness of the specimens 

 and their holes and tubular cavities," says Professor Kupert Jones, 

 " appear to have suggested to the old Flint-folk of the Valley of the 

 Somnie, that they might be used for beads; such perforated forms 

 are frequent in the gravel that yields the flint axes. I may add" 

 (he says) "that the imperforate forms occur in the gravels just as 



Fig. 1. Porosphccra globularis, Phillips, reproduced by the author's kind 

 permission from pi. i of paper by Dr. G. J. Hinde, F.E.S. (Journ. Roy. 

 Micro. Soc, 1904, p. 1-25). 



much as the perforate. Also that the perforation of the non-drifted 

 specimens in the Chalk is often just as smooth and straight as if 

 artificial ; the interior sui-face is not ivorn, however, but consists of 

 the natural structure of the organism." (April 22, 1862.) 



Dr. G. J. Hinde, F.R.S., in his valuable memoir on ForoHphcera 

 (Journ. Roy. Micro. Soc., 1904, pp. 1-25, pis. i and ii) says that 

 Dr. A. W. E.owe, F.G.S., in his researches on the fossils from the 

 different zones of the Chalk on the east and south coasts of England 

 has met with many hundred examples of Porosphaira which he had 

 placed in Dr. Hinde's hands for examination. This little sponge is 

 common in the chalk cliffs of Yorkshire, Kent, Sussex, Isle of Wight, 

 Dorset, and South Devon. 



Dr. Hinde writes: "I may mention that within the limits of 

 a moderately-sized garden situated on the slope of a chalk down at 

 Croydon, Surrey, I have during the last sixteen years picked from 

 the surface-soil 632 specimens of different forms of Poroi^phcBra which 

 have all been derived by slow weathering from the underlying Chalk." 



