338 
TUE OEOI-OGIRT, 
and a-half inches broad, the snb-caudal about five and a-lialf inches 
long by seven and three- qixarters inches bi'oad. By compainng 
this with the CarmylHe specimen, it must have belonged to an 
animal about six feet in length. 
From the same quarry, and about the same time, I was also for- 
tunate enough to procure five very nearly complete segments and 
part of a sixth of another rterijgotus avfjUcus, the segments of which 
lift quite out from the matrix, leaving a very thin cast. A seventh 
segment is also sho\vii in this specimen, lying at nearly right angles 
to the others ; this might, however, have belonged to another animal 
coming out entire and separate from the other segments. This speci- 
men would seem to have formed part of an animal considerably 
broader in proportion to its length than the two before described : in 
this respect it agrees with another very fine specimen now in tlie 
museum of the Watt Institution of Dundee, found some two years 
ago in a quarry on Tealiog, consisting of seven of the body segments 
of the Fterijgotus anglicus. 
These four are by far the most complete remains of this veiy 
curious crustacean yet found ; besides those of this species, P. angli- 
cus, only very fragmentary remains of another species of Pterygotus, 
P. imndatus, have yet been found in Forfarshire. In Cauterland 
Den, however, and the " fish-beds" near Farnell, several specunens of 
a Pterygotus very similar in appearance and form to the P. anglicus 
have been discovered, but of a comparatively very small size, being 
only six to ten inches in length. These have not as yet been ex- 
amined and named by any competent authority. They are all pre- 
served in the collections of the Rev. Henry Brewster, of Farnell, and 
the Rev. Hugh Mitchell, of Craig. 
After the repeated notices of the Farnell " fish-bed" in the " Geo- 
logist," by Mr. Mitchell, it is unnecessary for me to give any length- 
ened description of this very curious deposit or its peculiar fossils. 
It was first noticed as affording evidences of being fossiliferous, and 
pointed out as such by Mr. Brewster. It is, however, to the indefati- 
gable researches of Mr. Mitchell that we are indebted for a know- 
ledge of the curious organisms it contains. It is at present being 
very fully explored. The Earl of Southesk, on whose estates it is 
situated, has not only allowed this to be done, but has, with the 
greatest liberality, furnished labourers for the heavy part of the 
work, placing the examination of its treasures in the hands of Mr. 
Brewster and myself; and it is only due to his lordship here to 
record our grateful thanks for the unexampled facilities it has 
afforded for having these treasm-es, so long locked up, made known 
to the geological world. 
Besides a good many specimens of the genei'a Acanthodes and 
Br achy acanthus, discovered and noticed by Mr. Mitchell, several 
species, apparently new, of Diplacanthtis, with the remains of other 
fishes of other genera have ah-eady been discovered, as also several 
cm'ious and seemingly new species, if not genera, of Eurypteridce 
and other crustaceans. These are in the course of being prepared for 
