Revietos — Dr. Roice'n Zones of the White Chalk. 171 



in a few years much light will be thrown on these problems, of such 

 interest to geologists in general. 



I wish to thank Dr. Kitchin and Dr. Thomas for valuable help 

 during the preparation of this article, and also Mr. J. W. Tutcher for 

 the care he has given to those of his photographs appearing in the 

 plates. 



EXPLANATION OF PLATE VI. 



Caninia coenucopijE, Mich. 



Fig. 1. — Fully grown adult of regular form (C. ' cornu-bovis'). Tournai. Geol. 



Surv. E.G. 3."1. 

 Fig. la. — Key diagram to segments cut from above. 

 Figs, lb and Ic, Id and le, 1/and 1^. — Lower and upper surfaces of segments ii, iii, 



and iv respectively. 

 Fig. Ih. — Longitudinal section of segment v, cut down the cardinal fossula (right- 

 hand side of figure) . Dissepiments partly obscured by intersections 



of septa (shaded) in the plane of section. 

 Fig. li. — Counterpart of Ih. Tabulte outside fossular depression. 

 Fig. ly. — Lower surface of segment vi, showing ring of dissepiments, and, to right of 



fossula, a fragment of epitheca repeated by rejuvenescence. (Micro. 



section.) 

 Fig. Ik. — Calyx (segment vii). 



Except the diagram. Fig. hi, all the above are very slightly enlarged 

 ( X if)- ^b-lj are from camera lucida drawings. ^ 

 Fig. 2. — Adolescent calyx. The common form at Tournai, representing the original 



conception of the species (conclusion of dmnonti phase). Shape of 



corallum as in lower part of Fig. L Tournai. Brit. Mus. Nat. Hist. 



E. 11,680, X f. 

 Figs. 2a-d. — Serial sections below same, showing characters of the dmnonti 



phase.- X 3. 

 Fig. 3. — Adolescent calyx (near ' Lophophyllum diimonti'). Tournai. Brit. Mus. 



Nat. Hist. R. 11,672. x |. 

 Fig. 4.— Adult calyx {' Zaphrentis edivardsiana,^ de Kon.). Rim broken down, 



showing dissepiments round base of calyx. Brit. Mus. Nat. Hist. 



R. 11,688. x f. 



Errata. 

 p. 26 (January Number), line 20 from top of page, for * Aa ' read ' 4^.' 

 p. 71 (February Number), line 19 from top of page, for ' inner' read 

 ' minor.' 



E, E "V I E "W S- 



I. — Zones of the White Chalk of the English Coast. By 

 Dr. A. W. KowE. Proc. Geol. Assoc, 1900-1908. 



AGrEOLOGIST, more confident of his hammer than his pen, 

 friend and rival of Lyell in the establishment of the theory of 

 actual causes, associate of Ami Boue in the foundntion of the Geological 

 Society of France, profoundly and permanently influenced the direction 



1 The segments are, of course, opaque, and the septa consequently appear white on 

 a dark ground ; in the drawings, liowever, this colouring is reversed, to secure 

 uniformity with the transparent microscopic sections 2a-2d and Ij. 



* Strictly speaking, only Figs. 2d and Id are in the dmnonti phase. Figs. 2b, 2c, 

 and lb, Ic, being in the vermicularis phase. 



