Page:Quarterly Journal of the Geological Society of London, vol. 32.djvu/294

214 214 W. J. HARRISON ON THE OCCURRENCE

parallel. The upper surface of the Eed Marl, however, is somewhat uneven, being hollowed out here and there in long curves. There is a slight dip to the south-east. The bed which I consider to be the lowest member of the Rhaetics is No. 2 in the accompanying section (fig. 1). It is a light buff-coloured hard sandy marl, some 16 feet in thickness, often of a greenish tint, with blue nodules here and there in the lower part. It is very much fissured, and has a conchoidal fracture. It is traversed by three or four courses of harder, whiter stone, which weather out from the rest, and are more laminated. Crystals of selenite are plentiful in this bed ; and I have also speci- mens from it of pseudomorphic salt-crystals, and a slab showing ripple-marks. Small fish-scales are numerous, and dark brown markings as of vegetable matter. I have obtained a single insect- wing from this bed. Pittings, as of rain-drops, occur in all parts, aud the upper surface is very uneven. This lowest Rhaetic bed ex- tends for some distance to the north and east of the Spinney Hills.

On the uneven upper surface just mentioned rests the bone-bed, a stratum not more than 2 or 3 inches in thickness. This bed is not easy to note on the " face" of the working, which is usually in a very " mashy " soft condition ; and I had much difficulty in finding it. On digging back some distance it becomes comparatively hard ; but its contents are then so brittle as to be very difficult of extrac- tion. For the detection of the numerous small teeth,, scales, &c. which it contains I have found the best plan to be to take home baskets full, which can then be sorted and examined at leisure with a lens. From this bone-bed I have obtained large vertebrae of Ichthyosaurus, numerous fragments of rib-bones, one probably of Plesiosaurus, about 18 inches long, together with numerous unde- termined bones, some of which have a Labyrinthodont character.

Spines of Xemacanthus monilifer and Hybodus minor, teeth, scales, &c. of Hybodus, Acrodus, Saurichthys apicalis, Sargodon tomicus, Gyrolepis, Ceratodus, large Saurian teeth, worn and rolled bones, phosphatic nodules, coprolites containing fish-scales, &c. are all of more or less frequent occurrence in this bed. I have found in some coprolites small quartz pebbles, and fragments of sandstone pre- cisely resembling the Upper Keuper Sandstone of the Dane Hills, on the opposite side of the Soar valley.

Pebbles of all sizes are numerous in this bone-bed. They are mostly quartzose or slaty, and rounded ; many are 3 or 4 inches in length; and I should refer them all to our Charnwood- Forest rocks. All the bones are highly mineralized, being heavy, and of a brownish colour. Small concavo-convex bodies are common, much like Discina in appearance; these are probably the ends of bi- concave vertebrae, of w T hich the central part has decayed away.

Two small bivalve shells (Axinus elongatus and A. depressus) occur loose in the bone-bed ; they also occur in the " flinty bed " at Beer Crowcombe *.

Next above the bone-bed come about 2 feet 6 inches of coarse black shales (No. 4 in section), very pyritous, the fossils being
 * Quart. Journ. Geol. Sop. vol. xvii. p. 503.