Reviews — Geological Survey Memoirs* 523 



The Chalk forms the basement rock of the district ; it comes to 

 the surface in the bottom of some of the main valleys, but is very 

 rarely exposed iu section. Although unquestionably the Upper 

 Chalk, no fossils are recorded. The Lower London Tertiaries 

 (Thanet, Reading, and Oldhaven Beds) crop out only to a slight 

 extent in the same valleys. Two of the finest sections may be seen 

 on the left bank of the Gipping, in the large chalk-pits north of 

 Bramford. Here London-clay and newer deposits are shown, rest- 

 ing on the Eeading Beds, Thanet Beds, and Chalk. The occurrence 

 of Oldhaven Beds appears to be limited to the town of Ipswich. 

 These Lower London Tertiaries are interesting from a stratigraphical 

 point of view, but their fossil treasures are few or but little known. 

 Mr. Whitaker expresses the hope that more attention may in future 

 be paid to these strata. 



The London Clay extends beneath the Crag and Drift over much 

 of the southern and eastern portion of the ai"ea, though its outcrop 

 is almost wholly confined to the valleys. It is well exposed in 

 many brickyards, presenting its ordinary characters of blue or brown 

 clay with septaria, underlaid by its " basement bed," which is gene- 

 rally very sandy and has often a layer of flint-pebbles. Among the 

 fossils a few shells, teeth of Lamna, remains of turtles, and fragments 

 of wood have been found. The most interesting section in this 

 formation was that at Kingston or Kyson Quay, in the valley of the 

 Deben. This section was originally noted by Mr, S. V. Wood in 

 1839, and he then obtained from the basement-bed of the London- 

 clay some small teeth resembling those of a Bat ; also a portion of 

 a small marsupial, Didelphys Colchesleri (discovered by Mr. William 

 Colchester), and a portion of a lower jaw, containing the last molar 

 tooth, which Sir Richard Owen described as that of a Monkey 

 [Mncacus Eoccenus), but which was subsequently proved to belong 

 to Hyracotherium. Referring to the extent of the older Tertiary 

 beds, Mr. Whitaker remarks that the evidence of well-sections 

 proves that these strata occur along the whole of the eastern border 

 of Suffolk. 



To the collector, the beds of Crag have always furnished the chief 

 attraction in Suffolk Geology. In the area under consideration the 

 Coralline Crag occupies a very limited portion of the ground, being 

 exposed only at Tattingstone, Sutton, and Ramsholt. The sections, 

 however, are of considerable interest ; that at Sutton shows about 22 

 feet of the Crag, with (at the base) phosphatic nodules, bones of 

 cetacea, teeth of sharks, box-stones (with Diestian fossils), etc. A 

 general account of the Coralline Crag is reserved for a Memoir on 

 the district around Aldborough, etc. 



The Red Crag occurs over a large part of the Ipswich district, 

 generally with a narrow outcrop at the higher part of the valley- 

 flanks, being otherwise much masked by Glacial Drift.' A general 

 account of this formation is given, of its phosphatic nodules or 

 " coprolites," of its organic remains, and of the unfossiliferous sand 

 out of which in many cases the shells have been dissolved. The 

 nodule-bed is of a conglomeratic character, like that at the base of 

 the Coralline Crag, the most peculiar of the rock-contents being the 



