Reviews— C. E. Be Ranee's Water Siqjphj. 85 



may be found in a single order of Mammals, and is no more than 

 might be expected in a sub-class of Reptiles. 



Among the families included in the present classification, I have 

 retained three named by Huxley {Scelidosauridcs, Iguanodontidce, and 

 Me.galosauridcB),^ although their limits as here defined are somewhat 

 different from those first given. The sub-order Compsognatha, also, 

 was established by that author in the same memoir, which contains 

 all the more important facts then known in regard to the Dinosauria. 

 With the exception of the Hadrosauridte, named by Cope, the other 

 families above described were established by the writer. 



The Amphisaiiridce and the Zanclodontida, the most generalized 

 families of the Dinosauria, are only known from the Trias, The 

 genus Di/strophceus, referred provisionally to the Sauropoda, is like- 

 wise from deposits of that age. The typical genera, however, of all 

 the orders and sub-orders are Jurassic forms, and on these especially 

 the present classification is based. The Sadrosauridoe. are the only 

 family confined to the Cretaceous. Above this formation there 

 appears to be at present no satisfactory evidence of the existence of 

 any Dinosauria. 



I^ IB ATI IB "W S. 



I. — The Water Supply of England and Wales. By Chaeles 

 E. De Range, Assoc. Inst. C.E., F.G.S., etc. Royal 8vo. pp. 

 623 ; 6 Coloured Maps. (London : Edward Stanford, 1882.) 



THE necessity of a ready and easily accessible water supply has 

 been probably the most common cause (although other causes 

 may have sometimes operated) in determining the sites of habitations, 

 villages, and towns in former times. 



Professor Prestwich has shown that the early growth of London 

 followed unerringly the water-bearing gravel (from 10 to 20 feet in 

 thickness) of the Thames Valley, eastwards towards Bow, White- 

 chapel, and Stepney ; north-eastwards towai'ds Clapton, Hackney, 

 and Newington, and westwards towards Kensington and Chelsea; 

 while northward it came for many years to a sudden termination 

 where this bed of gravel ends abruptly and the London Clay comes 

 to the surface, and occupies all the ground to the north. On the 

 outskirts of London, a succession of villages grew up on the great 

 beds of gravel ranging on the east, on the north along the Lea 

 Valley, on the west, and on the south of the Thames, while the old 

 habitations of Hampstead and Highgate are due to the water-bearing 

 Bagshot Sands which cap these elevations; again, where the permeable 

 gravel of the Boulder-clay series covers the London Clay hills to the 

 north, we have the old settlements of Hendon, Finchley, Barnet, and 

 other villages. (Ann. Address Geol. Soc. 1872, pp. 29-31.) 



The extension of Metropolitan London upon an increased water 

 supply is clearly indicated by the coloured Map given by Mr. De 

 Ranee (p. 179), showing the areas built upon at different dates from 

 ' Quart. Journ. Geol, Society of London, vol. xxvi, p. 34, 1870, 



