Vol. 67.] THE AVONIAN OF BURRINGTON COMBE. 391 



EXPLANATION OF PLATES XXVIII-XXXI. 



Plate XXVIII. 



[Fig. 6 is magnified about 25 diameters, and all the others about 15.] 



Fig. 1. Concretionary limestone showing what appear to be interlacing tubules 



(? calcareous alga) (31). S 2 top ; Quarry 1. (See p. 345.) 



I. Oolitic and iorannniferal limestone (33). S 2 top; Quarry 1. (See 



3. Penecontemporaneously brecciated horny limestone (20) S • hill 



side between Quarries 1 & 2. (See p. 346.) 2 ' 



4. Penecontemparaneously brecciated oolitic and foraminiferal limestone 



(3). S 2 base ; Quarry 2. (See p. 347.) 



5. Foraminiieral and crinoidal limestone (12). 2 ; near the Cave. (See 



p. 348.) v 



6. Limestone in process of dolomitization (132). C x ; Quarry 3. (See 



p. O'iO.) 



Plate XXIX. 

 [Fig. 6 is magnified about 25 diameters, all the others about 15.] 

 Fig. 1. Limostone in process of dolomitization (149). C. ■ Quarry 3 The 

 unaltered limestone is grey, the dolomite black ill the photograph 

 tion ^ (See Pa 348) are ^ ^ r ° Ck " sll ' Ce due to fau ^ prepara- 



2. Crinoidal limestone' (< Petit Granit') (63). C x ; hillside between 

 Quarry 3 and the Great Scarp. (See p. 349 ) 



'•^strtt 1 U (Se e e S 7 3 9 51 W ) th ^"^ ^ *■ ' WeSte ™ '«"" 



5. Coarse oolite (139). K : ; eastern twin-stream. (See p 352 ) 

 6 '^^ a ^ tvi ^ MtrM °^(^)' K i5 Wes ^rntwin- S tream. (See 



Plate XXX. 



[All the figured specimens are from the Burrington section, and are 

 magnified 1£ times.] 



Figs, la & 16. Sections from the same specimen. Zapkrentis cf. parallela 

 Carruthers (p. 372). From Horizon 8. paraueia 



Fig. 2. Zapkrentis densa Carruthers (p. 373). From C 



Figs. 3 a & 3 b. Sections from the same specimen ? Caninia sp. or ? Zapkrentis 

 cf. parallela (p. 372). From Horizon 3 y ^mentis 



T7- c d k 7 l 2 ' gs ' 46 & ic > from Horizon y. 



1 igs. 5 a & 5 b. Caninia patula Micb., de Kon., & Salee (p. 374) The widel v 



septate form. From Horizon y. ^ J J-iie wuiely- 



Figs. 6 a & 6 b Caninia patula Mich., var. (p. 375; see also text-fig U 



p. 3/o). Tbe closely-septate form. From the base of Horizon y. ' 



Plate XXXI. 



[All the figured specimens are from the Burrington section Fi^s l o allfl fi 



are of the natural size ; the others are magnified 1£ times.]' ' 

 Fig. 1. Caninia cylindrica (Scouler) Salee (p. 376) From C 



2. Cyathophyllum (?) ' » Vaughan (p. 379). From Horizon y. 



3. Early Clisiopbyllid (p. 380). From Horizon y 



