HANDBOOK OF FOSSILS. 79 



NOTES ON THE DIFFERENT FORMATIONS MEN- 

 TIONED IN THE TABLE. 



RECENT. The alluvial deposits of most river valleys and 

 some estuaries still in course of formation, containing fossil shells 

 and mammals, all of living species. 



QUATERNARY, POST-PLIOCENE, or PLEISTOCENE. i. In- 

 cluding the raised beaches around the coast, the older gravels of 

 river valleys and the cave deposits, in all of which the shells are 

 identical with those living in the rivers and seas of to-day, whilst 

 the animals are many of them extinct, only a few being now 

 found living on the spot. 



2. The glacial drifts that cover all England north of the 

 Thames, and which consist of sands, gravels, and clays, full of big 

 angular stones frequently flattened on one side, scratched and 

 sometimes polished from having been fixed in moving ice and 

 forced over other rocks. A very interesting collection of these 

 "boulders," as they are called, can be easily made, for they belong 

 to almost every formation in England, and have some of them been 

 brought from great distances, whilst the number and variety ob- 

 tainable from a single pit is astonishing. 



CAINOZOIC, or TERTIARY. Beds of this age, in England at 

 all events, are for the most part made up of comparatively soft 

 rocks, gravels, sands, and clays, and are found in the eastern and 

 south-eastern counties. They are divided into 



I . Pliocene, mainly consisting of a series of iron-stained sands, 

 with abundant shell remains, and locally known as "crags." 

 The shells are very partial in their distribution, the beds in places 

 being almost entirely made up of them, whilst in others scarcely 

 one is to be found. The great majority are of the same species 

 as many still living. The Pliocene is subdivided into three 

 groups : 



a. The Norwich Crag Series, sometimes called the " Mam- 

 maliferous Crag," as at its base the bones of mastodon, elephant, 

 hippopotamus, rhinoceros, and some deer have been found. 

 The shells in it are such as still abound on the beaches of the 

 eastern coast to-day whelks, scallop shells, cockles, periwinkles, 

 etc. 



b. The Red or Suffolk Crag, its two names indicating its 

 characteristic colour (a dark red-brown) and chief locality. 

 From the base are obtained the celebrated phosphatic nodules 

 miscalled " Coprolites," whence is manufactured an artificial 

 manure, and with them are found the rolled and phosphatized 



