Correspondence — Mr. E. Ray Lanhester. 47 



Waveney and Little Ouse, first as one valley, then as two valleys, 

 then as two valleys inosculating. But the iipper part of every so- 

 called river valley on earth is always purely a " rain valley or dry 

 valley " sine flumine vallis, as in myriads of cases entire valleys are, 

 especially in porous-strata like Chalk. And in nature, at the dividing 

 ridge, each opposite dry valley or water-flow may be seen to stretch 

 its fingers up each opposite water-slope to join hands across the in- 

 tervening water-parting. Hence the low parts of a dividing ridge 

 alternating with high parts, for which we have the modern northern 

 terms, gap, saddle, col, &c. Hence the southern sierra or serra (saw), 

 and the Latin " juga montium," from the saw-like, or yoke-like ups 

 and downs of dividing ridges. The very name of jugum (hill or 

 yoke) originates here, But these opposite dry valleys, which run up 

 to these low parts of the dividing ridge, these beginnings of valleys 

 are not caused by rivers. They are caused by the cause of rivers — 

 rain. Geokge Greenwood, Colonel. 



Brookwood Park, Alresford, December 7, 1868. 



THE MAMMALIA OF THE CEAG. 

 Sir, — I observe that the Eev. 0. Fisher, at page 547 of your last 

 number, states, on the authority of the Eev, J. Gunn, that Elephas 

 meridionalis occurs in the Red Crag. He also speaks of the " Crag 

 period" in such a way as to make it clear that he regards the terres- 

 trial Mammalian fauna of the Suffolk Bone-bed as identical with 

 that of the Mammalian Norfolk Crag. It has always been to me a 

 matter for much regret that the able students of the Norfolk Crags 

 will not give due attention to the facts known as to the Suffolk 

 Crag, for by their assistance the students of the latter might hope to 

 unravel the mysterious history of that strange deposit, the Eed Crag. 

 What grounds have the Eev. John Gunn and the Eev. 0. Fisher for 

 stating that E. meridionalis is found in the Eed Crag ? The only 

 elephant tooth supposed to come from the Eed Crag — known to the 

 late Dr. Falconer — is referred by him to E. antiqims (Palajont. Mem. 

 vol. ii. p. 181), and there is no real reason for believing it to be a 

 Eed Crag specimen at all. It is true that Mastodon Arvernensis is 

 common to the Norfolk and Suffolk deposits ; but have you in Nor- 

 folk Bhinoceros ScMeiermacheri, Hycena antiqua, Hipparion [TJrsus 

 arvernensis is, I think, found there) ? Though the character of the 

 lowest beds of the Suffolk and Norfolk deposits is similar, there 

 seems to me, at present, reason to regard the terrestrial Mammalian 

 fauna of the Suffolk Bone-bed as older than that of the Norfolk Crag 

 generally. It is most important to remember that they are older than 

 the Coralline Crag. E. Eay Lankester. 



ON THE OCCUERENCE OF TITANIUM, ETC., IN MAYO. 

 Sir, — I have lately discovered a new locality for the mineral 

 Titanium, viz., on Cushcamcurragh, a mountain in the townland of 

 Treel, near Newport, Mayo. It occurs in the form of fine crystals 

 of Eutile, imbedded in quartz and schist, in the neighbourhood of a 

 landslip of considerable extent which took place last year at the head 



