THE SIZEWELL CRAG by H .
E. P.
SPENCER
SINCE the exposure of Crag was made known by Capt. A. E. P. Spencer who noted it while using the Territorial Rifle Range, it has been visited several times as it was found to be of unusual character compared with other Crag sections. T h e exposure is a very small one but is exceptionally rieh in molluscan remains and in particular is quite unlike any Norwich Crag found in Suffolk during the Pit Survey. Permission to work it should be obtained from the Adjutant of the 4th Bn. Suffolk Regt., (Territorial), T h e Drill Hall, Ipswich. It is important to ascertain when the ränge will not be used for firing as the section is close to the 100 yard firing point and cannot be worked while shooting is in progress. There is a number of overgrown disused pits on the common which might pay for reopening. T h e Sizewell Crag is notable for having yielded the only known Rhinoceros fossil from the Norwich Crag ; it is a last Upper molar, M3, which does not resemble any of the Red Grag species and has not yet been determined. T h e list given by Mr. David Long is a valuable addition to our knowledge of the site and it is hoped additions will be made to it as further work is done.
THE
ALDEBURGH
TRANSITIONAL
CRAG
T h e Crag deposit intervening between the Bryozoan Rock Bed of the Coralline Crag and the " Chillesford Clay " at Aldeburgh Brickyard, is another deposit on which it is desirable that further work should be done. Among the reputed fish vertebrae one belonging to a marine mammal was found ; it is a caudal vertebra of a Dolphin, Tupsiops (Delphinus) tursio (?) Bonnaterre. Similar bones are recorded from Coralline, Red and Norwich Crags, also the Cromer Forest Bed Series. It is curious that only caudal vertebrae appear to have been preserved as no others have been observed in collections. T h e species is still living in the Atlantic.