1867.] Geology and Paleontology. 415 



clay in Norfolk," which he considers to be more recent than 

 the true Boulder-clay, and even than the plateau-gravel of the 

 district. 



In an important paper " On the Age of the Lower Brick-earths 

 of the Thames Valley," Mr. Boyd Dawkins grapples with a subject 

 which has been a fertile source of discussion since the year 1836. 

 These deposits were considered by Dr. Falconer to be anterior in 

 age to the Boulder-clay, and by Mr. Prestwich to belong to the 

 Low-level series of Quaternary deposits. The sections at Ilford, 

 Grays Thurrock, Crayford, and Erith all show the following 

 deposits in ascending order: (1) the fluviatile brick-earths and 

 gravels, whence the Mollusca and Mammalia are derived, and which 

 are remarkable for the horizontality of their bedding and the even 

 sorting of their component parts ; (2) the " trail " of Mr. Fisher, of 

 a highly confused nature, and as remarkable for the contortion of 

 its bedding as the deposits below are for their horizontality ; (3) the 

 surface-soil resting on the uneven summit of the preceding. These 

 three deposits indicate three epochs : First, that of the brick-earths, 

 in which the water was unencountered by floating ice ; then that 

 of the trail, which is probably a mere icewash formed under a 

 glacial climate ; and lastly, the rainwash, formed under temperate 

 conditions. The presence of Elephas priscus and Bhinoceros 

 megarhinus indicates the affinity of this group of deposits to those 

 of Preglacial age on the Norfolk shore, and to the foreign Pliocenes. 

 The tichorhine and leptorhine Khinoceroses, on the other hand, 

 point towards deposits of clearly defined Postglacial age. The 

 preglacial Trogonthere, Bhinoceros etruscus, Elephas meridionalis, 

 Sorex moschatus, and Cervus dieranios are absent on the one hand, 

 the entire group of Postglacial Arctic Mammalia on the other ; and 

 especially among these latter the Beindeer. The Lower Brick- 

 earths therefore afford remains in part peculiar to the forest-bed of 

 Norfolk and the Pliocenes of France and Italy, and in part to the 

 Postglacial deposits, and probably occupy a middle point in time 

 between the two, being more modern than the former and more 

 ancient than the latter. For these reasons the author suggests the 

 following classified list of Pleistocene deposits : (1) Forest-bed of 

 Norfolk — climate temperate ; (2) Lower Brick-earths of the Thames 

 Valley — climate temperate; (3) Glacial deposits — climate severe; 

 (4) Postglacial deposits — climate severe, but gradually becoming 

 temperate. 



Mr. Maw's paper " On the Occurrence of Consolidated Blocks 

 in the Drift of Suffolk " is a contribution to the evidence on the 

 geological position of the blocks of saccharoid sandstone which are 

 found scattered on the surface of many parts of the chalk-districts, 

 and which appear to have been derived from several formations of 

 different ages. In the author's opinion the blocks now treated of, 



