W. B. Lang — Lower Plienshachian of Charmouth. 411 



the fossils for the most part are poorly preserved, and are not 

 easy to find in place, however they may abound in fallen blocks. 

 The commonest fossil is Inoceramus falgeri, Merian in Escher von der 

 Linth,^ a large form described from Lias above the Sinemurian of 

 Lechthal, iN.E. Switzerland. Several species of Ammonite have 

 been found, but await identification. Since different horizons have 

 yielded different kinds, it is hoped that if the species can be determined, 

 it will be possible to draw zonal lines in this middle division with 

 some exactness. Belemnites are common throughout. The bottom 

 division — the Lower Pale Band — itself is sometimes divided by three 

 still paler beds. It comes to the beach at Ridge Water, and owing 

 to the reversal of the dip at this point rises on to the cliff on each 

 side. It is thrice thrown down again on the east by the small 

 step-faults already mentioned (p. 404) between Eidge Water and 

 the big llidge fault. The Middle Pale Band is easily recognized by 

 being always divided by three paler beds and two intervening darker 

 beds into five stripes. This feature is constant throughout the whole 

 of its exposure from the western side of Black Ven to the Ridge 

 fault; whereas the Lower Pale Band is only sometimes thus divided, 

 and the Upper Pale Band, if differentiated at all, breaks up into 

 a large number of beds. The Upper Pale Band is the thickest of the 

 three, 8 feet as compared with 5 and 4 feet respectively for the 

 Lower and Middle Pale Bands. It becomes somewhat darker in its 

 upper part, and tends to pass into the Upper Dark Band. In its top 

 portion it contains Uptonia aff. Ironni (Roemer).^ At about three- 

 quarters of a mile east of the mouth of the Char, the Upper Pale 

 Band is seen to split into about sixteen alternating lighter and darker 

 stripes, but generally it is more or less uniformly pale. 



The Upper Marls on the whole are dark. The bottom bed, how- 

 ever, a 2 ft. pale band, is conspicuously contrasted to the 1 ft. 

 Upper Dark Band of the Middle Marls, and with it forms a convenient 

 because easily recognized division between the Upper and Middle 

 Marls. Above the 2 ft. pale band are 8 feet of darker marls, 

 then 3 feet of dark Belemnite Shales, and finally 3 feet of marl 

 with much pyrites capped with the Belemnite Stone. The 3 feet 

 of Pyritic Marl are almost certainly the beds whence liave come 

 ammonites of the valdani group, ^ preserved in pyrites, that are not 

 uncommonly found on the terrace below the Belemnite Marls. So 

 far but one of these has been found by the author in place — 1 foot 

 below the Belemnite Stone. It is probable, then, that the line between 

 the jamesoni and ibex-valdani zones will be drawn in the lower part 



^ A. Escher von der Linth, " Geol. Bemerkungen u. d. nordliche Vorarlberg 

 und einige angrenzenden Gegenden," 1853, p. 1, pi. i, figs. 1-5. See also 

 W. Ooster, in C. von Fischer-Ooster, " Protozoa Helvetica," vol. i, pt. ii, pi. xii, 

 figs. 1-5, pp. 36, 37, 1869. I am indebted to my colleague, Mr. E. B. Newton, 

 for kindly identifying this form. 



2 The following additional note was added by Mr. S. S. Buckman, who 

 kindly identified this form: "? = youngof d'Orbigny's large figure of Uptonia 

 regiiardi," d'Orbigny, 1842, Pal. Franc?. Terr. Jur., p. 257, pi. Ixxii, fig. 1. 



^ Mr. S. S. Buckman has kindly examined this form and identified it with 

 Acanthojpleuroceras ellipticum (James Sowerby), "very near to A. valdani.'^ 



