302 Dr. H. Woochcard — A Neiv Greensand Crab. 



The Editor of the Complete Farmer ssijs : " Obstacles to the work 

 sometimes fall out from the light contexture of the soil, which does 

 not unfrequently give way to the destruction of the chalk drawer. 

 To the farmer it may be of consequence to consider the nature of his 

 land ere he embarks on the scheme of husbandry ; as, if from the 

 circumstances above mentioned, he may have reason to think his 

 pit will not stand firm, it would be a matter of prudence to desist 

 from any further thoughts of sinking a perpendicular pit, and 

 change the mode of operation by bringing his chalk from an 

 uncallowed pit or (open working), but where it can be obtained 

 at a moderate expense, and with a tolerable certainty of success, 

 the preceding method is certainly the most eligible." 



The writer does not wish to occupy more space by "hammering 

 a driven nail." It must surely be apparent to all those of logical 

 mind who have read and explored both sides of the question that 

 no mystery exists with respect to the " dene holes " in Essex. 

 The whole class of these excavations have their origin and inception 

 of design in the very ancient custom of " bell pit " mining. It 

 might be argued, not unfairly, that the same system of working, 

 identical in general design, may have been made use of for other 

 purposes than for chalk quarries merely ; that is, assuming that 

 further evidence exists of their having been so used, which, however, 

 remains to be discovered with respect to the Essex " dene holes." 



The writer thinks we may safely say that where such collateral 

 evidence does not exist, and pits of this description are discovered 

 from which the chalk has been removed and carried away, that the 

 balance of probability in favour of their having been merely chalk- 

 pits is overwhelming. 



DESCRIPTION OF PLATE XL 



Modern Dene Holes and their makers at work in the " Purbecks " of Brightling, 

 Sussex. Picture shows four pits in all stages of working and completion. 



IV. — On a New Species of Brachyurous Critstaoean from the 

 Chert Beds (Upper Greensand), Baycliffe, near Maiden 

 Bradley, Wilts. 



By Henry Woodward, LL.D., F.E.S., F.G.S., etc. 



HAVING, in March last, received from Mr. Jukes-Browne, F.G.S., 

 of the Geological Survey, a small carapace of a crab obtained 

 by Mr. J. Scanes, of The School House, Maiden Bradley, from 

 a quarry in the Chert Beds of Baycliffe, near Maiden Bradley, 

 Wilts, I endeavoured to identify it with some species of Cretaceous 

 Necrocarcinus already described, but without success. I am therefore 

 reluctantly compelled to refer it to a new species. The specimen is 

 rather imperfect, which renders the task of determining its characters 

 the more unsatisfactory. 



The carapace appears to have been nearly equilateral (31 mm. long 

 and 30 mm. broad) ; the right side is, however, imperfect, and the 

 edge of the posterior border is also wanting. The surface is tumid, 



