Reviews—Guide to the Fossil Invertebrata. 519 
the oldest, as they might be seen in a continuous section across the 
country if one walked in a more or less straight line from east to west. 
Examples of the rocks themselves are placed on the shelves below, 
accompanied by numerous small sections of the strata as seen by 
observers in various parts of England. Affixed to the wall-cases is 
a series of small maps of Britain, each coloured to show the tract of 
country where the particular rock-group is exposed at or near to the 
surface, of which specimens are exhibited in the adjoining case. In 
the long section, at the top of the case, the number placed beneath 
each bed gives its approximate thickness in feet. 
In connection with the subject of British strata reference is made 
to the important work done by William Smith, surnamed the ‘‘Father 
of English Geology,” who was the first in this country to demonstrate 
the now fully recognised fact that each group of strata is marked by 
certain fossils. Therefore, when once a geologist knows the fossils 
characteristic of the various strata he can, if set down in any part of 
the country, readily determine on which bed in the geological series 
he is standing, if only he can find a few fossils to aid him. They are, 
in fact, the unerring ‘spoor’ to the geological hunter to guide him to 
his ‘quarry.’ A very good portrait of Smith is given in the Guide. 
This gallery is a veritable monument to William Smith; on the south 
wall is a copy of the original map geologically coloured by himself, and 
still in many respects a reliable guide. In the centre of the east wall 
is his bust (surrounded by maps and sections prepared by him) and 
surmounting a glazed case and cabinet containing his original collection, 
a monument to his genius as an original investigator and to his 
unwearying labour as a worker. In this gallery are also shown the 
collections of Mr. Searles V. Wood from the Crag, Mr. Edwards’ from 
the Eocene, Mr. Sowerby’s types of the Mineral Conchology, 
Dr. Davidson’s Brachiopoda, Gilbertson’s Carboniferous fossils, 
Brander’s Eocene shells of Hampshire, Mr. Konig’s types, and the 
few identifiable fossils of Sir Hans Sloane’s Museum, the nucleus of 
the original British Museum (1753), 
Nor do these important ‘type’ and stratigraphical collections 
exhaust this gallery, for at the further end, in wall-cases 6 and 7 
and on the walls and opposite side, are brought together a very 
interesting series of specimens illustrating the work of dynamical, 
chemical, and organic agents—some caused by earth movements on 
a large scale, such as may be observed in the squeezing and crumpling 
of great masses of strata often miles in extent and thickness, as seen 
in mountain chains such as the Alps, the Andes, and the Himalayas, 
illustrated by models prepared by Lord Avebury and recently 
presented by him; others showing minute movements producing 
small faults, folds, and cleavage planes in rocks of various ages. Of 
chemical and concretionary structures there are again very many and 
varied examples, illustrated by ‘dendritic markings,’ ‘ cone-in-cone ’ 
structures, and a very wonderful series from the Magnesian Limestone 
of Durham, chiefly collected by Mr. G. Abbott, F.G.S., offering the 
most curious mimetic representations of organic structures, such as 
Stromatopora, and Corals in great variety, as well as globular and 
botryoidal forms. Many concretions also have organic nuclei, such 
