nXPI.ANATION OF PLATHS 



I'lr,. lA — Srilioii of Wi-nlock I.imcslone x 17 Diam.. May Hill, Gloucestershire. 

 sluiws tV:ll;lln■Mt^ of C.ilranciiis orjjanisnis niicloscfi in crusts of Girvaiiellje, thus formin<j 

 ojranulcs. Owiii"; to a difcit in the iicijntivc tliis illustialion is not so clear as could lie 

 flcsircd. 



Pig i|.. — Portion of the crust of the ii]i]icrniost Q:ranulc in l-'ifr. ta x 70 Diam 

 Shows the (iirvaiicll-i,- Tuhulcs whn li form the crust The lower portion of the 

 liLIure is the calcareous fraunicnl shown in the centre of the Ujiperniost jr^'mle in 

 lit; lA This is a new form of Girvanella here descrihcil for the lirst time. 



Fio. 2A, — Section of (I'lrhoniferous Limestone from tlii' luiildle series, (".lifton. Uristol, 

 y '{2 Diam. Shows the Limestone to he made u|> of the niinnti- fragmcntal remains of 

 mi<rosco|iii- life, niostlv I'oraminifera and ('.alcis]ih;vr:v. Sonic of the former are well 

 preserved and can he easily distiuf^uished, hut the (-alcispha'r.-v ap|iear as verv minute 

 rino:s requirinfj a magnifying j;lass to see them clearly 



Frr,. 2ii. — A portion of hi;: 2a ■ 65 L)ianr This hiijher niapjuihcation shows one 

 of the foran\inif<Ta, .-ind frasjments of others, also si'veral sections of Calcis|)ha'rn.' wliieh 



ajipear in rings. 



Fig. 3A. — Section of iMiteheldeania incrustinj; a fra<;ment of shell x 9 Diam. F'roni 

 the Lower Carhonif< lous Limestone Shales. Dryhrook. (iloucestershire 



I'lG. 31! Tangential section of Mitcdielileania Nicholsoni x 70 Diam., shewing the 

 minute structure. From the C^arhoniferous Lower Limestone- Shales. Dryhrook, 



Gloucestershire. 



Fk;. |a. Section of Inferior Oolite Leekhainpton Hill, near Cheltenham x 16 Diam 

 Shows Iragnii iital reiuains of Calcareous organisms enclosed in crusts of (jirvanella;, 



thus illustrating the formation of oolitic granuli-s. 



Fig. ,.|I!, Sections of portions of the crusts of two of the granules in 1-ig 4A. 

 showing the GirvanelFv tuhulcs x 70 Diam The two crusts touch <-ach other. The 

 ligliter |i:nt on tlie left is a portion of the nui Icnis of one of the granules 



