372 



TflE GEOLOGIST. 



and though the upper part makes but a poor road-stone, tte lower 

 affords a tolerable building material, and slabs of large size are sometimes 

 quarried. At ^Torton and Coomb Hill, and still farther on the road 

 towards Tewkesbury, and at Brockeridge Common, near that town, and 

 thence to Defford, these strata may be traced, and many pits are 

 worked ; and the student, in order to make himself acquainted with 

 them, should trace them from the latter place, following the line of 

 quarries to Brockeridge. In this part of the series, the greatest number 

 of saurian reptiles have been found, even entire skeletons of the most 

 frequent species of Ichthyosaurus and Plesiosaurus, the /. communis and 

 P. doUchodeirus. The presence of these marine lizards indicates a 

 somewhat different condition of the sea at that period ; and the wonderful 

 state of preservation in which they have been discovered, probably 

 shows that they were suddenly entombed and rapidly covered up in the 

 calcareous mud with which the waters were highly charged. It is a 

 curious fact that in all parts of the world where the Lias is present, 

 the remains of these formidable reptiles have been met with, proving 

 their wide and extensive distribution throughout the sea at that epoch. 

 Their fierce and predaceous habits have been already alluded to ; and a 

 few observations may now be added with regard to their structure. The 

 jaws of the Ichthyosaurus were armed with pointed teeth ; the eyes 

 were of great size, protected by moveable sclerotic bony plates, and 

 possessed of great and very distinct powers of vision, beautifully 

 adapted to the nature of a reptile which inhabited deep as well as 

 shallow water, and occasionally, also, basking on the shore. The head was 

 unusually large, and the neck comparatively short ; the vertebrte were so 

 constructed that they permitted quick and rapid motion, after the 

 manner of fishes. The tail was long and tapering, with a vertically- 

 placed terminal fin. The movements of the body were ably aided by 

 four paddles. Thus, in all its parts, this creature combined the 

 characters of a fish and a reptile. The largest specimens must have 

 attained the length of upwards of forty feet, and may truly be afiirmed 

 t) have been the most formidable monsters of the ancient deep. The 



1)0 seen elsewhere ; mul many fossils may be procured. There is, also, a small 

 patch of Llaf, still hi;^hcr in the series, at Pyrton, on the opposite side of the 

 bevorn, full of ft)ssils ; and this spot is particularly interesting, as it exhibits 

 the junction of the Lias with the upper Ludlow roclcs, which are brought up here 

 by a fault and crop out on the banks of the river a little farther to the west.— 



r. B. r>. 



