246 B. B. Woodward— 



This, to say the least, is suggestive that here is another case of 

 irregularity compensated for in the total. 



The outcome of this plotting went to show that whereas at first 

 sight the body- whorl appeared to be proportionately much larger 

 than the precediug ones present, and consequently to indicate 

 Cerithoid affinities, the actual fact when the missing portion was 

 restored showed no such great discordance and consequently 

 suggested that relationship lay rather with the Tiaridae. No member 

 of this family exhibits anything approaching the column-like form 

 of the Wealden giant, but some species of the type genus are 

 proportionately extremely elongate and many-whorled and often 

 carinate above the periphery. There are faiut indications that the 

 fossil here described was similarly carinate just above the periphery. 

 Both the Potamidina? and the Tiaridae have comparatively thin 

 shells, while their inner structure is often thinner than their exterior 

 would lead one to suspect. 



If the foregoing conclusions be correct, as we believe, many 

 interesting questions naturally arise. How could this colossus of 

 its class have thus suddenly appeared and again disappeared, 

 unforecast, and without descendauts ? What did it feed on, and' 

 what preyed on it ? Such questions cannot at present be answered, 

 but anyhow a fossil of such importance as this merits a name and 

 such description as the material to hand renders possible. Hence 

 we would propose to designate it : — ■ 



DiNOCOCHL"EA INGENS, n.gen.et sp.i 



Shell (at present represented only by its cast) dextral or sinistral) 

 elongate cylindrical : whorls, about twenty-three iu number, 

 increasing very slowly in size from the apex to the peniiltimate, 

 and slightly more rapidly in the last and the body whorl ; faintly 

 carinate just above the periphery. External characters, aperture 

 and operculum unknown. 



Formation and locality. — -Wadhurst Clay (Wealden), near Hastings, 

 Sussex. 



Dimensions {approximate, taken from the dextral specimen). — 

 Alt. 222 cm. (= circa 7 ft. 3 in.) ; diam., first whorl 10-3, second 

 whorl 13-3, twentieth whorl 28, body-whorl 32 cm. On a rough 

 calculation, the shell tube if uncoiled must have been over 60 ft. in 

 length. 



The shell was evidently proportionately very thm, as iu some of the 

 recent Tiaridae, so that on its dissolution the ponderous cast, while 

 yet in a plastic state, shrank on itself, obliterating for the most part 

 the interval which should have been left between the successive 

 whorls and by the columella, a phenomenon also observable in some 

 of the seams of casts of Viviparus shells belonging to the same 

 horizon. 



* As usual in these cases, the generic includes, and should be taken as, the 

 specific description as well. 



