THE PRESIDENT'S ADDRESS. 153 



Bechei, and striatum come out in great force therein. The Upper Lias 

 contains a remarkable preponderance of the genus Harpoceras, such as 

 falciferum, serpentinum, bifrons, ovatum, and variable with Lytoceras and 

 Stephanoceras, in variable proportions of specific forms. 



These few examples are sufficient to illustrate the general character 

 of the laws that determine the distribution in time and space of the 

 Ammonitidae of the Lias, and teach us that new groups of chambered 

 shells fill the different zones of the Lias, which have no genetic 

 relations with the forms that prevailed in Triassic times. 



The Gastropods and the Lamellibranchs of the Lias follow the 

 same general law of distribution as the Ammonites ; the three great 

 divisions of Liassic time having their own groups of organisms apper- 

 taining to these classes, and strictly limited to them. 



The Grinoids of the Lias deserve some special notice, seeing that 

 they differ so widely from the Triassic form of Encrimu moniliformis. 

 The genus Pentacrinus suddenly makes its appearance in the Lower 

 Lias sea in the form of P. tuberculatum ; in the Middle Lias we have 

 P. robustus and P. briareus, the latter covering large slabs with its 

 numerous arms on the Dorsetshire coast ; in the Upper Lias we find 

 that remarkable species Pentacrinus Hiemeri, whose long stems, many 

 feet in length, are coiled beneath the calyx. I have seen in the 

 Stuttgart and Tubingen Museums many wonderful examples of this 

 species, which have long stems many yards in length. 



Many beautiful examples of Ophiuridce and Asteriadm are found in 

 the Lias, and some fine sea-urchins, resembling existing species ; but 

 my limits forbid me entering upon the description of these interesting 

 fossils ; enough, however, has been said to convince you that the Lias 

 contains a magnificent succession of life, embedded in strata that 

 succeed each other in regular order without those breaks in the 

 continuity of deposition which render the geological record imperfect in 

 some other formations, but which in the case of the Lias presents us 

 with a regular superposition of the stratigraphical series from the 

 bottom to the top, and affording a faithful record of ocean life during one 

 of the most remarkable periods of Mesozoic time. 



The Cotteswold Hills form an elevated tract of land, having an 

 average elevation of 750ft. above the sea level, and extending in a 

 north-easterly direction through the county of Gloucester, rising 

 abruptly from the plain, and presenting a bold escarpment to the 

 north-west. The outer line of these hills commences near to Bath. 

 and undulating first westward and then northwards for upwards of 

 sixty miles, terminates in the bold headland of Ebrington Hill. 



The southern section of the chain is of inconsiderable height, but 

 towards Wotton-under-Edge Symonds Hall Hill rises to 810ft. and 

 Standish Hill 715ft., which runs out into the conspicuous promontory of 

 Stinchcombe Hill, 725ft. high, stretches far westward into the 

 valley, and from its wooded sides and turf-clad summit some of the 

 finest panoramic views of Gloucestershire are obtained. North of 

 Stinchcombe the chain recedes easterly, and forms a deep bay, 



