KENNAED & WOOBWAED : HOLOCENE SHELLS FEOM IGHTHAM. 265 



in the Pleistocene deposit, whilst the holocene and recent examples of 

 Helix nemordis and R. hortensis are by no means so fine as the older 

 specimens. Four species occur in the Pleistocene, but are unknown 

 later — Pyramidula ruderata, Hygromia umhrosa, Jaminia muscorum, 

 and Succinea oblonga. One species, Selicella itala, occurred in the 

 Pleistocene and in the tumulus, but is quite extinct in the neighbour- 

 hood at the present day. Helix aspersa occurred in the tumulus, but 

 not in the Pleistocene, and is of course too abundant livino;, whilst 

 Helicella cantiana must be considered a recent immigrant, since it is 

 absent from both deposits, though common Jiving. The band formulas 

 of Helix nemoralis from the tumulus are : — 



12 3 4 5 .. 



.. 

 003 .. 



(1 2 3)(4 6) .. 



1 2 3 (4 5) .. 

 3 4 5 .. 

 003 4 .. 



Nineteen examples. 



Eight example 



Three examples. 



Two examples. 



Five examples. 



One example. 



One example. 



These figures are very similar to those of the Pleistocene examples, 

 the only noticeable difference being that 3 was far more abundant 

 in Pleistocene times than later. The example of 3 4 5 is perhaps 

 noteworthy, for this is a rare mutation in England, though far more 

 common in the west of Ireland. The band formulae of Helix hortensis 

 from the tumulus are : — 



12 3 4 5 Two examples. 



00000 One example. 



We have to tender our best thanks to Mr. Benjamin Harrison, of 

 Ightham, for kind assistance during the examination of the tumulus. 



Allens Farm, Ightham. 

 Mr. F. J". Bennett, F.G.S., kindly forwarded us some material from 

 a holocene deposit situate on Allens Farm, Ightham. Although the 

 exact age of the deposit is uncertain, yet the contained mollusca are 

 of some interest. Twelve species were noted : — 



Zmaa; fltrJorww, Bouch.- Chant Six examples. 



Arion ater {Lmn.) Common. 



Vitrea cellaria {}ivi\\.) Four examples. 



Hygromia hispida {hinn.) One example. 



Vallonia pHlcheUa\}i\\\\.) One example. 



Fyramidula rotuudata (Mixll.) Common. 



Helix nemoralis, Linn. Fragments. 



Vertigio pusilla, M.ul\. One example. 



CarychitMn miniiiiKiii, ^lilll. ... ... Common. 



Acicula lineata (Drai^.) Two examples. 



Zimnceatrnneatula, Midi Two examples. 



Fisidium casertaniim (Poli) ... ... ... One valve. 



Of these the two most noteworthy forms are Acicula lineata and 

 Vertigo pusilla, both of which are extremely rare in Kent in a living 

 state, whilst it may be noted that both these species, as well as Limax 

 arborum and Arion ater, are absent from both the tumulus and the 

 Pleistocene of the fissure. 



