340 
THE GEOLOGIST. 
believe that a greater number really exists. No fossils belonging to 
this class appear to have been found at Petherwin or Barnstaple ; 
nor are any of the species known to belong to the Silurian or Carboni- 
ferous series. Polished sections frequently show these organisms 
surrounding foreign bodies, in most cases corals. 
in 1843, Mr. Peach brought certain fossils, which Mr. Couch had 
then recently discovered in slate-rocks near Polperro in Cornwall, 
before the Geological section of the British Association, during its 
meeting at Cork. They were pronounced to be ichthyolites ; and 
this, perhaps, the more readily from the fact that whilst the con- 
temporary rocks of Scotland had yielded fossil-fish in great numbers, 
^s^o more than, if so much as, the faintest trace of organisms of this 
class had been found in Devonshire and Cornwall ; and this without 
the appearance of any reason for such absence. 
Mr. Peach traced these fossils from near Fowey harbour to Talland 
sands, about two miles west of Looe. Subsequently they have been 
found, at by no means wide intervals, along the entire coast of Corn- 
wall from Talland sands to Rame Head, near Plymouth sound. They 
have also been met with, but in small quantities, at Cliff on the left 
bank of the river Fowey, at Bedruthen on the north coast of Corn- 
wall, and at Mudstone Bay, near Brixham, in South Devon. 
Specimens were sent to the late Mr. Hugh Miller, who, at first 
inclined to confirm their ichthyic claims, — stating, indeed, of one 
specimen, that If he had found it in the Lower Old Red Sandstone 
of Cromarty, he would have no hesitation in regarding it as a frag- 
ment of some dermal plate of Astcrolepis ;" but on receiving a larger 
and more complete series, he prepared a paper on them, which was 
read before the Royal Physical Society of Edinburgh, in which he 
" doubted whether their true place in the scale of being had been 
determined," and pronounced them " the most puzzling things he 
had ever seen ; riddles on which to exercise the ingenuity of the 
palseontolog-ist." Soon afterwards Professor McCoy and Mr. Carter 
subjected them to a close microscopic scrutiny, which resulted in the 
fossils being pronounced to be sponges merely. A new genus, 
Steganodidyum, was established for their reception, of which they 
were found to constitute two species, 8. cornuhicwn and 8. Carteri. 
These fossils are found in slate-rocks only. 
The remarkable fossil formerly known as 8phceronites tesselatus, 
has also experienced a variety of fortune among systematists. 
Rumour says it has been assigned to Inseda. In a note to Sir R. 
T. De la Beche's paper on " The Geology of Tor and Babbacombe 
Bays," the late Mr. Broderip says " It is not impossible that the 
fossil here referred to may have belonged to the Tunicata* Professor 
Phillips, after Mr. Austen, placed it, provisionally, amongst the 
Sphoeronites, a genus of the family Cystidese, belonging to the 
Cystoidea, an extinct order of Echinodermata. Sir R. I. Murchison, 
more recently, says, " It is not, however, a Cystidean, that family 
* Trans. GeoL Soc, 2ncl series, vol. iii., part 1st, p. 164. 
