32 UK. A. M. DAVIES ON THE KIMER1DSE CLAI [Feb. I907, 



It will be most convenient to describe these in descending 

 order. 



8. Zone of Exogyra virgula. — There can be no mistake 

 about this zone, as specimens of the zone-fossil can be picked up 

 by hundreds on the weathered surface. The majority are more or 

 less broken, but a good number of perfect valves can be found, 

 with occasionally a bivalved specimen. I have verified their occur- 

 rence in situ in the uppermost 4 feet of clay, but it is not easy to 

 collect except from the weathered surface : this may be the reason 

 for the small number of species collected, as shown by the 

 following list : — 



Ichthyosaurus (fragment of rib). 

 Aptyclius lotus, Park. 

 Exogyra virgula, Defr. 

 Exogyra nana, Sow. 



Serpula convoluta, Goldf. 

 Cytheridea ('!). 

 Cristellaria, two species. 

 Vagiaulina sp. 



7. — The clay immediately below the virgula-zone is very similar 

 lo the virgula-cl&y itself, but contains abundant crushed shells, 

 among which Perisphmctes and Lucina were apparently recognizable. 

 Verj r few other fossils were obtainable except microscopic forms, 

 which abounded just at the base of the clay, immediately above 

 Hie upper limestone-band. The following is the complete list : — 



Crinoid-ossicle. 

 Echinoid-spine (minute). 

 Xodosaria, two species. 

 Vaginuliua sp. 

 Cristellaria, two species. 

 \ax sp. 



Vertebra of fish. 

 Aptyckus lotus, Park. 

 Perisphinctes (1). 

 Lucina, (?). ' 

 Ct/theridea ('.). 

 Cytherella (?j. 



The upper portion of this clay was much obscured by slipping at 

 "the times when I examined it. It contains some large septaria l 

 near the top (unless these had slipped down from the virgula-zone, 

 as is possible but not likely). The clay varies from grey to blue- 

 grey in colour, has much 'race' in places, and elsewhere contains 

 lenticular crystals of selenite, measuring from 0*5 mm. up to nearly 

 2 cm. in diameter. The lenticular form appears to be due to a 

 combination of the hemipyramid (111) with what may be either 

 the hemi-orthodome (103) or the hemipyramid (113), the cur- 

 vature of this surface being so great that it is impossible to say 

 whether it is one face or two. 



6, 5, & 4. — The two limestone-bands are so exactly alike in 

 character, that it is impossible to say from which of them any fossil 

 was derived — the fossils having been either picked up among the 

 broken pieces of stone or obtained from the workmen. A micro- 

 scopic section of a piece of limestone shows nothing but a minutely- 

 crystalline aggregate of calcite with flecks of brown (argillaceous) 

 matter. A fragment dissolved in acid left a very fine argillaceous 

 residue. 



1 Mr. R>. W. Pocock has called my attention to the fact, that some of the 

 crystals of calcite lining the fissures in these septaria exhibit the rhombo- 

 .hedron impaled on the scalenohedron. 



