76 REPORT— 1868. 
What may be called imperfect diamonds are also found; the most important of 
these is the “ Carbonate,” which is now commonly used in cutting diamonds. 
The diamond-workings of the Chapada had, twenty years ago, the town of Santa 
Isabel as their centre; since then they have moved northward to Lencoes, now a 
city, and have extended more than thirty miles beyond it. 
There seems no reason why the yield of diamonds should decrease so long as the 
present price is maintained ; new localities, not only in the Chapada, but in other 
parts of the province, as at Pitanga, near Bahia, already noticed, will be found when 
required, and the province maintain its reputation of being the main source from 
which the market is supplied. The value of diamonds raised cannot be accurately 
determined, since only a small part comes to Europe through the regular channels, 
but it may probably exceed £500,000 in favourable seasons, ¢. e. when water is 
abundant. 
On the Fossil Fishes of Cornwall. By C. W. Pracn, A.LS. 
In 1841 the author read a paper at the Meeting at Plymouth on Cornish Fossils, 
in which he said that he had found, at “ Punch’s Crossquarry Fowey, portions of fish 
remains.” At the Meeting at Cork in 1845 he exhibited finer and better specimens, 
some of them found by Mr. Couch at Polperro, and still considered them portions 
of fishes, and was supported in this opinion by the late Professor H. Forbes and 
others present there. Up to 1849 he did all possible to extend his researches, 
and on eas sides of the county he was fortunate enough to get fish-remains. In 
December of that year he left Cornwall, and has not been there since. Fishes 
these things were considered until 1855, when Professor M‘Coy, after a visit to 
Cornwall with Professor Sedewick, stated, in ‘The British Paleeozoic Fossils,’ 
published at Cambridge, “ that he had carefully examined some of the specimens in 
the museums of Penzance and Truro, and many others that he had collected ; 
and had sections prepared for the microscope, and had come to the conclusion 
that they were not Fishes, but Sponges, of which he made out two species.” Up to 
April last they have been considered so, when Mr. i. Wyatt Ndgell, in a letter in 
the Geological Magazine, asserted that the so-called Steganodictyum, or sponges, 
of M‘Coy, were true fishes, belonging to Pteraspis, and since Professor Huxley, 
and Messrs. E. Ray Lankester, Salter, and Woodward have stated the same. Thus, 
then, although these fossils have been so long under a cloud, light has broken in 
upon them, and now their true history will be told by Messrs. Powrie and E. Ray 
Lankester in their beautiful monograph of these hitherto obscure Pteraspid forms. 
Since learning the change of opinion, he turned out the contents of a box packed 
in Cornwall in 1849, and, amongst a few pretty specimens of fish-remains, found 
a splendid but imperfect cephalic shield of Pteraspis, six inches in length; it is 
beautifully marked with delicate waved lines, and shows tubercles and cancel- 
lated structure. As it isso much larger than any figured in the monograph aboye- 
mentioned, no doubt it will prove anew species. Although he has remained silent 
so long, his opinion has never changed as to the fish-nature of these remains ; and 
in all his rambles over the rocks of the Old Red Sandstone in Scotland, with the 
exception of one small piece, tuberculated like the dermal plate of a Coccosteus, 
and also the cancellated structure in the decayed bones of Osteolepis, he has found 
none like the Cornish ones. The same network cancellated structure is to be seen 
in carboniferous fishes. This structure deceived Professor M‘Coy and others, and 
hence their objection, because no similar appearance is known in the bone of any 
living animal. 
On the Condition of some of the Bones found in Kent's Cavern, Torquay. 
By W. Prncutty, B.S. 
In this communication the author confined himself to the marrow-bones ¥ hich 
occur in the Cavern, and which present themselves in four different conditions— 
Entire, Crushed, Fractured, and Split. 
The first, having but little information to give, he dismissed in a very few words. 
The second were found at al] levels, and invariably beneath huge blocks of 
limestone which had fallen from the roof; thus indicating that they were crushed 
i 2 oe 
see Te 
