Reviews — Geological Structure of Vale of Kingsclere. 183 



consists of 3 unequal infrabasals (the small one right posterior), 

 5 basals, 5 radials, a radianal (forming the lower part of r. post E..), 

 and a long anal x. This last rises in a spearhead between the 

 adjacent arms ; the other arms are separated by similar spearheads, 

 formed from both shoulders of the anterior radial and the right and 

 left shoulders of the right and left posterior radials; the antero- 

 lateral radials have no such processes. The arms consist of 

 2 primibrachs followed by equal rami of 3 secundibrachs, except in 

 the antero-lateral rays, which have but one primibrach. The tumid cup- 

 plates and the short square brachials of the short arms give the 

 crown a massive appearance, despite its small size. 



Dr. Springer assigns this new genus to no Family, and is, indeed, 

 uncertain as to the Order, though describing it as a Dicyclic Inadunate 

 " intermediate between the Larviforma and the Fistulata". If by 

 this he means phylogenetically intermediate, he is deriving dicyclic 

 forms from monocyclic, which is unjustified. He excludes it from 

 the Flexibilia because there is "no indication of loose suture or 

 flexibility in cup ortegmen". None the less Mysticocrinus would 

 seem better placed in that Order. The tegmen in any case is 

 unknown, and in so small a cup it Avould be hard to see any indica- 

 tions of loose suture. The anal x recalls that of Lecanocrinus, as 

 Dr. Springer says, also that of Anisocrinus. The tightly-closed arms 

 resemble those of Lecanocrinus and still more those of Mespilocrinus. 

 The inadunate character of the arms is primitive and is paralleled by 

 Pycnosaccus, which has wide interbrachial areas occupied by small 

 irregular plates. That genus and Lecanocrinus also display a 

 tendency to have a single primibrach instead of the two usual in the 

 early Flexibilia. The primitive position of the radianal is retained 

 also in the Silurian Flexibilia, Clidochirus and Ichthyocrinus. 



When Dr. Springer's great Monograph of the Flexibilia reaches 

 this country we shall see to which of his Families Mysticocrinus 

 might be referred. Its " mysterious " characters are due partly to 

 its primitive stage of development and partly to conditions, probably 

 of a reef-like nature, such as have so often produced similar forms. 



F. A. Bathek. 



IV. — Notes ok the Geological Structure of the Vale of Kings- 

 clere. By H. L. Hawkins. Proc. Hampshire Field Club, 

 vol. viii, pp. 191-212, with 4 plates, 1918. 



rpHE author gives an interesting sketch of the stratigraphy of the 

 1 Vale of Kingsclere, with a general account of the development 

 of the Cretaceous and Tertiary deposits. As a result of his palseonto- 

 logical work in the Upper Chalk, he proposes to subdivide the 

 coranguinum zone, which is of unwieldy proportions, by marking off 

 the upper portion as the "sub-zone of Conulus alhogalerus " . Some 

 modifications are also suggested in the reading of two well-sections, 

 affecting the assignment of certain beds to the London Clay and 

 Heading Beds respectively. The most important part of the paper, 

 however, is concerned with the tectonics of the district. A detailed 



