Geology and Mineralogy, 



^4^1 



Simple Bivalves. 



Gen. No. of Species. 



Anomia - - 1 



Cardium (echinatum) - 2 



Chh.ma . - i 



A reversed var. of Cliama 

 squamosa, i. e. the lower 

 or adherent valve turns 

 the contrary way. , 



Donax - - 1 



Lima - - 1 



Lucina (divaricata) - 2 



Lutraria - - 1* 



Gen. 



Mactra 



Modiola 



Nucula (rostrata) 



O'strea 



Panopae^^ 



Pinna 



Psammotea ? 



Pholas (cuspatus) 



Tellina 



Venu* 



Pullastra 



No. of Species. 

 1 

 1 

 2 

 2 

 2 

 1* 

 1 

 1 

 4 

 5 

 1 



The above shells are from the Crag formation, and are in addition to 

 those published in Mr. Taylor's article (p. 26.) ; I am not aware they have 

 hitherto been anywhere published. — S.V. W. Woodbridge, March, 1829. 



Geological Hammer. — Sir, Having had occasion 

 for the use of a geological hammer, which should 

 unite the qualities of power and compactness, it 

 occurred to me, that an elastic handle, applied to 

 one of Knight's Trimming Hammers, would effec- 

 tually answer my purpose. I therefore selected one 

 of that kind which is marked No. 5. in Knight's 

 plate and description of Geological and Mineralo- 

 gical Instruments and Apparatus {fig. 74.), and, 

 removing the handle of wood, attached it to an 

 elastic handle of leather, and it has answered ex- 

 tremely well, during a long campaign amongst the 

 rocks of Germany, serving every purpose which I 

 wished it to serve. 



The construction of the handle is as follows : — 

 Three narrow slips of soling leather having been se- 

 lected of the length most convenient, I caused them 

 to be firmly glued together, so as that the grain of the 

 exterior pieces should be in a different direction from 

 that of the enclosed piece. The whole was then 

 rounded, and reduced from the extremity upwards, 

 till it fitted the aperture in the metal, and then by 

 two small wedges of wood driven in between the 

 slips of leather the whole was firmly secured. The 

 handle was then strongly bound with twine, round 

 and round, from the one end to the other. I would 

 certainly recommend this plan in preference to a 

 vine-wood handle, or any other, as it is not liable to 

 break, possesses a nearly perfect elasticity, and pre- 

 serves its shape. — W. B. Clarke. East Bergholt, 

 Suffolk, Nov. 24. 1828. 



Schorl, dark-coloured mica, slate (except it is very light-coloured), and 

 many other minerals, attract the magnetic needle, after being exposed to the 

 reducing flame. In some cases it is sufficient to attach a fragment of the 

 mineral to be examined to the end of the platina wire, by means of a part 

 of the moistened powder of the same substance ; in others, the whole must 

 be reduced to powder, and a little borax added before it is exposed to the 

 flame, to enable it to act upon the needle. This character, which is useful 

 in leading us to a knowledge of one of the component parts of a mineral, 

 as well as enabling us to distinguish it from others, appears for the most 

 part to have escaped the observation of mineralogists, at least it is seldom 

 noticed in their works. — W, H, M, 



