290 JURASSIC. 



hemisphccrictis, II. dcpnssus, CoUyrites ringens, Cidaris Bouchardii, 

 etc. The large specimens of Clypeus Plotii {siniiaius), called 

 poundstones or quoitstones, were in old times not unfrequently 

 employed as a pound-weight by dairywomen.^ They occur in the 

 upper beds at Stroud, Naunton and Stow-in-the-Wold, and appear to 

 be represented in Dorsetshire by C. alius. 



Several species of Scrpula are met with, also Polyzoa, and 

 spicules of Holothuroids. Among the IMollusca, the species of 

 Trigonia are very abundant : they include T. fonnosa, T. coslala, 

 T. sigtiala, etc. The Inferior Oolite was indeed termed ' the 

 metropolis of the Trigonias ' by Dr. Lycett. There also occur, 

 among the Lamellibranchs, Oslrea gregan'a, O. Marshii {flabelloides), 

 Lima pecliniformis {proboscidea), L. Elheridgii, Peclcn demissus, 

 Trichllcs, Aslarle excavala, A. obliqua, Ce7'07nya Ba/'ociana, Modiola 

 Soiverhyana, Hinniles ahjeclus, Myacites ienuislrialiis, M. Jui'assi, 

 Gresslya ahdiicla, Myoconcha crassa, etc. Among the Gasteropods 

 species of Pleiirolomaria are numerous ; Amherlcya, Chemnilzia, 

 Nalica, and other genera occur, also NerincBa and Alaria, which 

 appear for the first time in this country. Belemniles giganleus, B. 

 canalicidalus, etc., and Natililus Iruncalus, and other species are 

 met with. Remains of Fishes, Slrophodus and Acrodus, have rarely 

 been noticed ; bones of Saurians have also been met with. Plant- 

 remains are exceedingly rare, but Araucaria has been determined. 



In describing the Corals of the Inferior Oolite near Crickley and 

 Stroud in Gloucestershire, ]\Ir. R. F. Tomes observes that one bed 

 in the Oolite Marl has the appearance and character of a true reef.^ 

 Four distinct Coral-beds have been observed near Stroud by Mr. 

 Wi chell. 



The Inferior Oolite is best developed in the Cotteswold Hills in 

 Gloucestershire. At Leckhampton Hill, south of Cheltenham, it 

 admits of the following divisions (see Fig. 43):^ — 



6. Upper Ragstone | and Clypeus bed | 38 feet — Zone of A. Farkinso7ii. 



5. Lower Ragstone ( with C. Plotii. ] ,, ,, Hiimphriesianus. 



4. Upper (flaggy) Freestone 27 „ ) e,-,„>,-/,w 



3. Oolite Marl 7 „ i " " -^"'^''^y^- 



2. Lower Freestone no ,, ) .. 



I. Pea Grit Series 1% „ ] " ^^ MurcJnsomv. 



Prof. Hull estimated the total thickness of the Inferior Oolite at this locality to 

 be 264 feet ; Mr. Witchell, whose figures are quoted above, estimates it at 236 

 feet. The Upper Freestone is so intimately connected witli the Oolite Marl, that 

 Mr. Witchell would group them together. Ammonites are not abundant in the 

 beds. 



The beds 5 and 6 are sometimes divided as follows : — 



Clypeus Grits or Pholadomya Grit, with P. Heraulti and Ilomoinya gihbosa. 



Upper Trigonia Grit, witli T. cosiata. 



Gryphite Grit, with GrypJuva sitblobata {Bucktiiani). 



Lower Trigonia Grit, and Chemnitzia Grit with C. procera. 



1 Phillips, Life of William Smith, p. 3. 



- Q. J. xxxviii. 411 ; G. Mag. 1SS6, p. 385. 



3 E. Hull, Geol. Cheltenham; J. Lycett, The Cotteswold Hills, 1857 ; J. Buck- 

 man, Q. J. xiv. 107 ; T. Wright, Q. J. xvi. 5 ; Murchison, Geol. Cheltenham, 

 edit, by J. Buckmanand H. E. Strickland, 1845. 



