100 Proceedings of the Royal Physical Society. 
kindness, examined them, and informed me that they were 
Geodia ; the species he could not tell. He farther added, 
*' that he had found Geodia in a flint in the chalk ; therefore 
this sponge appears to be more ancient than had been sus- 
pected." We have Geodia zetlandica in our northern seas 
(see Johnston's " British Sponges," pi. iii., figs. 3 and 4, and 
described at page 195). I also met with that species in Corn- 
wall. The piece mounted in Canada balsam will show the 
spicula and siliceous globules. Here, then, was a reward ; 
for not only did the walk of at least thirty-two miles prove 
beneficial to the body — the mind truly enjoyed a feast ; the 
numberless objects of beauty that stud the path of the na- 
turalist makes all roads cheerful ; and if I were to add a list 
of the attractions of that day, it would, though interesting, be 
a long one. It will be sufficient for me to say, that the excite- 
ment caused by every new beauty drove weariness from the 
body — mind triumphed over all — and to me this was a 
" Queen's day" indeed ! The pleasure did not cease with the 
day, for my collection of stores has given me much useful 
employment since. Add to this, the satisfaction of knowing 
that I had turned up a new leaf in the history of this long- 
gone period. Long gone as it may be, its history is linked 
to the present ; for the ancient organisms of the seas of the 
clay period have direct descendants now living in our seas, and 
although from our present knowledge some may be wanting, 
either of the past or the present, the advancing march of re- 
search is fast lessening the number, and filling up the gaps. 
Geodia is not the only sponge from this formation which has 
come under my notice, for in many fragments of shells the 
excavations of Clionia are frequent. I send portions of a 
Cyprina and Buccinum burrowed by it. At present I have 
seen only a single spiculum, the colouring, and probably very 
minute portions of the sponge, and as well the peculiar small 
indentations in the excavations, " These indentations," Mr 
Plancock says, "are a very certain character which never 
fails to determine the habitation of the burrowing sponge, 
even though every particle of the animal be removed." Un- 
fortunately small fragments of shells only are met with ; these 
have been so much rubbed and washed, that the delicate por- 
