SCIENTIFIC SUMMARY. 
257 
Figures and a description have recently been published in the Geologist 
of a piece of hone which the editor assures us is a spear-head. It is 
phosphatized, and was picked up on a heap of phosphatic concretions from 
the Reg Crag. It is certainly of Crag age. Should the discovery of other 
and less equivocal weapons prove the existence of man in the Pliocene 
period, it would raise interesting speculations on recalling the feature of 
the Hindoo mythology, in which the elephant, supporting the world, stands 
on a tortoise, to remember that Chelonia atlas, which could have sup- 
ported one of the elephants, which existed with it, is found fossil in the 
newer Miocene. 
Mr. Stoddart has discovered in the Carboniferous Limestone of Clifton, 
near Bristol, a stratum twelve feet thick, almost entirely composed of 
microscopic fossils. From one pound weight of the rock were obtained 
one million six hundred thousand distinct and perfect fossils, besides a 
large quantity of broken shells and other fragments. But what gives an 
interest to the circumstance, is the fact that a large proportion of these 
specimens are minute univalve shells, of a twentieth, thirtieth, and for- 
tieth of an inch in length. These fossils are referred by the author to the 
genera Pleurotomaria, Turritella, and Euomplialus, though without any 
indications, either in the figures or descriptions, of the structures which 
characterize those genera. 
Students of star-fishes will be interested to learn that those singular 
Silurian forms included in the genus Protaster, which so nearly resemble 
some of our British stars, having, like them, slender arms attached to a 
circular disc, and having a similar structure of those arms, have been 
shown by Mr. Salter to have on the under side a double row of pores for 
the protrusion of tentacle feet, as in the common asteroid star-fishes. 
There is thus, as also in many of the minor points of structure, a blending 
of the characters of the two great groups of free star-like creatures. It 
is from this circumstance that the discovery has great importance. It leads 
to the expectation that when the contents of the palaeozoic rocks shall be 
better known, other forms will be found bridging over the gap, till now 
so wide, between the two orders. 
It has lately been shown by Harry Seeley that in much of the central 
part of England the Coral Rag is replaced by a clay. This formation has 
been named the Tetworth Clay. Instead of containing the fossils of the 
Coral Rag, it has a mixture of those most characteristic of the Oxford 
Clay below, and of the Kimmeridge Clay above, so thatthe three formations 
hitherto included partly in theUpper, and partly in the Middle Oolite, are 
so linked together as to form one great formation which has received the 
name of Fen Clay, from its constituting the great Fen district of Cam- 
bridgeshire and the adjoining counties. By the discovery of rocks similar 
to the Kelloway, though of less thickness, the Oxford Clay has been 
divided by the same author into upper, middle, and lower. The most 
important of these stone bands is the Elsworth rock, a limestone fourteen 
feet thick, which he regards as the uppermost stratum of the Oxford Clay 
series. 
