1896. THE PREPARATION OF CHALK FOSSILS. 311 



has this advantage, that the chalk can be afterwards treated with 

 water or hydrochloric acid without in any way impairing its strength. 

 The cement is soluble in benzol, and any bead of it which exudes 

 between joined surfaces can be rubbed away with cottonwool soaked 

 in that fluid, or flaked off with the point of a knife, or pared away 

 with a blade which has been heated in the spirit lamp. To detach a 

 specimen from its mount, it is only necessary to heat it, or to pass 

 under it an old flexible table-knife which has been heated. When the 

 chalk is soft, it is better to soak the bottom of the block with silicate 

 of potash, as otherwise the cement may adhere to the mount, and 

 drag away with it a layer of the chalk. A very useful aid to heating 

 awkward corners and angles of a specimen is to be found in the spirit 

 lighter, called a promethean, which is used to light incandescent gas 

 burners. 



Let me conclude by a plea for the more exact localisation of 

 fossils. For this one usually looks in vain, and " South of England " 

 seems to be considered near enough for all practical purposes. As to 

 zonal localisation, there is so little evidence of such a custom in high 

 places that it would be wonderful if it were commonly found in private 

 collections. But if a collector cannot name a fossil, or determine the 

 zone from which it comes, he can at least fix the exact locality ; and 

 this it is his clear duty to do, since many notable fossils lose half their 

 value from indiscriminate collecting. On this head Mr. A. J. Jukes- 

 Browne, in his paper on " The Subdivision of the Chalk," gives good 

 advice. He says : " Much, however, still remains to be done in com- 

 pleting our knowledge of faunas of the different zones, and everyone 

 who makes a collection of fossils from any part of the Chalk, and is 

 careful to record the exact zone and quarry where each specimen was 

 obtained, will be rendering valuable assistance." 



Arthur W. Rowe. 

 I Cecil Street, Margate. 



