ON CRETACEOUS POLYZOA. 391 
decrease in size from blocks of one or two feet in diameter, lying at the 
top, to very minute fragments, succeeded by still finer particles forming a 
clay bed; which in general reposes on the chlorite marl (Glauconite), 
This bank extends from the southern escarpment of the adjacent hills, 
which form part of the northern boundary of the Weald of Kent, in a 
gradual descent southwards for more than half a mile, where a hollow is 
formed occupying an area of about fifteen acres, and surrounded by Chalk 
detritus, except at one point, where a rivulet carries off the streams from 
the Chalk hills. In this hollow’ beneath the vegetable soil, and also under 
the banks of detritus, lies the clay-bed above mentioned, varying from one 
to twelve feet in depth, of a greyish colour and tough consistence, and 
containing nodules of undecomposed white and grey chalk and of ochreous 
and argillaceous substances. This bed, abounds with many varieties of 
Amorphozoa, Zoophyta, Annelida, Polythalamia, Entomostraca, &ec. 
. . . From its general and palxontological characters, this bed would 
seem to have been formed from the washings of the neighbouring Chalk 
hills at the time they received their present undulated contour.’ Pro- 
fessor Jones regards the ‘detritus’ as consisting mainly of Chalk marl. 
In their ‘Supplementary Monograph on Cretéceous Entomostraca,’ 
1890, Professor T. Rupert Jones, F.R.S., and Dr. George Jennings 
Hinde, F.G.S., further remark on the same bed at page vi, and on the 
Same page they refer to the ‘Greensand of Cambridge,’ thus: ‘This 
bed of glauconitic marl, formerly supposed to be on the horizon of the 
Upper Greensand, is now known to represent the so-called chloritic or 
glauconitic marl, and to be really the base of the Chalk marl, which rests 
here on an eroded surface of Gault.’ The Polyzoa of the ‘ Charing 
detritus ’ are so remarkably like those of the Cambridge Greensand that 
one naturally supposes a common origin for the two faunas. Some of the 
species which are common at Cambridge are rather rare at Charing ; but 
the most characteristic Polyzoa of the two deposits are Entalophora 
lineata, var. striatopora, Vine, and Umbrellina paucipora, Vine. These 
are rather common in both deposits. 
V. Potyzoa or THE Cuatx Derrrrus, Carine, Kenr. 
In his ‘Catalogue of British Fossils,’ Mr. Morris enumerated six 
species of Polyzoa from this deposit on the authority of Mr. W. Harris. 
I give these first :— 
1. Cricopora annulata, Reuss, Bohm. Kreid. pl. 14, fig. 2-3. 
2. Escharina dispersa, Reuss, Ib. pl. 15, fig. 26. — 
3. Hornera carinata, Reuss, Ib. pl. 14, fig. 6. 
4, Pustulopora echinata, Reuss, Ib. pl. 14, fig. 4. 
dD. »  madreporacea, Goldf., Blainy. ‘ Manuel,’ p- 70, fig. 5. 
Reuss, Bohm. Kreid. pl. 14, fig. 5. 
G6. Vincularia Bronnii, Reuss, Bohm. Kreid. pl.'15, fig. 30. 
The following temporary list of species, derived from the Jones-Harris 
material already alluded to, is given on my own authority. The list is 
neither classified nor complete :— 
