part 3] PLEISTOCENE DEPOSITS Allul M> CAMBRIDGE. 215 



piled-up gravel-heaps and one or two in situ, and a few more 



have been found by friends. None have been obtained from the 

 workmen, whom I have purposely kept ignorant of their existence, 

 so that there might be no danger of implements being brought 

 from elsewhere. I may state that I have visited the pits many 

 hundreds of times in the last eight years. 



Apart from implements, the only fossils found are of mollusca 

 -and vertebrates. The late Prof. H. (jr. Seeley states l that he 

 'found shells in the gravel under the Observatory,' but these 

 cannot be traced : for many years subsequently no molluscan 

 remains have been found in the Observatory gravels. In 1 !>!:>, 

 •one of the sand-filled channels of contemporaneous erosion near 

 the top of the unevenly-bedded series furnished a number of com- 

 pound concretions of lime-cemented sands of various sizes, up to 

 over a foot in diameter. 



In one of these Mr. K. A. Campbell, of Trinity College, dis- 

 covered two poor specimens of shell identified by Mr. Hugh 

 Watson as Pupilla muscorum (?). The find is sufficient to prove 

 that the upper gravel, at any rate, contained shells, and the record 

 i- u>efulasan indication of the possibility of discovering molluscan 

 remains in concretions when they do not occur in the normal 

 deposits. Similar concretions occur in sands of the lower series, 

 but have yielded no shells. 



Mammalian remains are also very scarce. I can find no bones 

 from these gravels in the Sedgwick Museum, and, during the period 

 when I have closely watched the excavations, only four have been 

 found by the workmen, namely, an astragalus of Cervus <'l<ij>ltns, 

 ii caudal vertebra of Rhinoceros?, and two teeth of JEqut/s. 1 do 

 not know from which series of deposits these were derived, save 

 that I was informed by the workmen who found one of the horse's 

 teeth, that it came from the basal gravel of the lower evenly-bedded 

 series. Implements, on the other hand, are relatively abundant. 

 It has long been known that they occurred in these gravels. 

 Sir .John Evans- states that 



'in the Woodwardian Museum is [a] flake, apparently of Palaeolithic date, 

 which was found in gravel near the Cambridge Observatory.' 



Two or three others have since been found, and with the former 

 are now in the Sedgwick Museum ; but the large series which J 

 have obtained in recent years is sufficient to throw some light 

 upon the ages of the implements, and therefore of the gravels 

 which have yielded them. 



Since 1911 I have obtained nearly 1000 pieces of worked Hints, 

 of which more than half were put aside, and several destroyed, 

 though a selection was kept to study questions connected with 

 patination and other matters. About 100 of the remainder may 

 be regarded as implements worked for a definite purpose, but 



1 Q. J. G. S. vol. xxii (1866) p. 475. 



- 'Ancient Stone Implements of Great Britain ' 2nd ed. (1897) p. boS. 



