318 RELATIVE AGES OF THE CRAG 



shells, the left side of the upper jaw of a Mastodon, contain- 

 ing the second true molar, and in the socket the indication of 

 another, namely, the first molar. This fragment was suffi- 

 ciently perfect to enable Mr. Owen, to whom I submitted it, 

 to refer it to Mastodon longirostris, a species also found at 

 Eppelsheim. With these remains of a huge pachyderm were 

 associated the teeth and jaw of a field-mouse, larger and with 

 stronger teeth than the common species, (Arvicola arvalis, 

 Cuv.). These fossils were accompanied also by the bones of 

 birds, together with remains of several fish, such as the Pla- 

 tax and Myliobates. The horns of stags, together with bones 

 and teeth of the horse, pig, elephant, and other quadrupeds, 

 have also been detected at Postwick, Thorpe, Bramerton, and 

 other localities of crag near Norwich. The association here, 

 as in so many other places, both in Europe and America, of 

 the remains of the Mastodon and horse, is remarked by Mr. 

 Owen as a subject not without interest. 



In addition to spots bordering the valley of the Yare, near 

 Norwich, I visited several others, such as Belaugh and Wrox- 

 ham, to the north of Norwich, and between that city and 

 Horstead. In all these I found the same kind of crag inter- 

 posed between the superficial gravel and the chalk ; the shells 

 consisting for the most part of Fusus striatum, Turritella te- 

 rebra, Cerithium punctatum, Pectunculus variabilis, Tellina 

 obliqua, Tel. calcarea, Cardium edule, and Cyprina vulgaris. 



Proportion of recent shells in Norwich Crag. — The infor- 

 mation which I was most desirous of obtaining respecting the 

 Norwich crag generally, was the degree of the resemblance of 

 its shells to those of the Suffolk crag on the one hand, and to 

 those of the existing seas on the other. In accomplishing 

 one part of this object, I have been particularly indebted to 

 Mr. J. B. Wigham, of Norwich, whose labours alone have 

 nearly doubled the number of shells which had been previ- 

 ously obtained from this formation, and who has most liberal- 

 ly placed his entire collection at my disposal. I have also to 

 acknowledge the assistance of Mr. Fitch, of Norwich. I re- 

 ceived moreover many shells of the Southwold strata through 

 the kindness of Capt. Alexander, several of them belonging 

 to species not yet discovered near Norwich. 



But it would have been impossible for me to compare the 

 Norwich shells, amounting to 111 in number, with those of 

 the Suffolk crag, had I not obtained the kind assistance of 

 Mr. Searles Wood, with opportunity of referring to his ex- 

 tensive collection. Nor would Mr. Wood and I have been 

 able to institute a thorough comparison of these shells 

 with recent species, if we had not been assisted by Mr. 



