H. Bolton—An Isle of Man Trilobite. 29 
semicircular smooth raised ridges, broader and shorter than the 
preceding ridge (by which indeed they are encircled), occupy the 
inner and more central portion of the shield, the outer one com- 
mencing near to, and the inner one on, the central ridge, at 5 mm. 
distance from the posterior border, and curving forwards until they 
touch the posterior ends of the two pairs of oval prominences near 
the front of the carapace. In the centre, between these raised 
ridges and the oval bodies, is a small lozenge-shaped area, which is 
continued backwards till it unites with the median ridge of the shield. 
The surface of the shield (particularly the posterior portion) is 
very finely granulated with minute circular and oval pustules (see 
woodcut, fig. B). No eye-spots are observable (unless a pair of the 
oval prominences in front may represent eyes? see woodcut, fig. A). 
There is no trace of any appendages to be discovered on the matrix. 
Observations.—Of the seven species of Cyclus already described 
by me, six are from the Carboniferous Limestone of Yorkshire 
and Ireland (see Grou. Mac. 1870, Vol. VII. pp. 554-558, Plate 
XXIII.) and one from the Coal-Shales of Carluke, Scotland (see 
Brit. Assoc. Reports, 1868, p. 72, pl. ii. fig. 1, and op. cit.). Several 
specimens, not yet described, were obtained, many years since, from 
the pennystone ironstone, over the thick coal, of the Staffordshire 
Coal-field, at Coseley, near Dudley, by the late Mr. Henry Johnson, 
C.H., F.G.S., of Dudley, and will be shortly described by me.’ 
In general outline this species from Bacup resembles most nearly 
Cyclus (Halicyne?) agnotus, H. von Meyer, sp., from the Muschelkalk 
of Rottweil, Germany (see Palaeontographica, 1847, vol. i. p. 234, 
pl. 19, fig. 23), but it differs in having an indentation or notch in 
the posterior border, whereas the German specimen has a small 
prominence. The arrangement of the ornamentation of the shield is 
similar but still very distinct. 
I have therefore no hesitation in treating this as a new species, and 
have named it Cyclus Scotti, after its discoverer, Mr. Geo. Scott, by 
whom it was presented some years ago to the Owens College Museum. 
VI.—Ow tHE Occurrence or A TRILOBITH IN THE SKIDDAW SLATES 
or THE IstE oF Man. 
By Herserr Bourton, 
Assistant Keeper, Manchester Museum, Owens College. 
HE series of slates, schists, and grits, of the Isle of Man, which 
are regarded as identical with the Skiddaw Slates of the Lake 
District, have hitherto yielded no traces of fossils, if we except the 
rare worm-like markings known as Paleochorda. The writer 
during the month of August last, took the opportunity of a visit to 
the island (in connection with the geological mapping by Professor 
Dawkins) to search very closely the least altered slates of the series 
along their northern outcrop. 
After a barren search of several days, two specimens of Paleo- 
chorda and the fragmentary intaglio cast of a trilobite were found. 
The specimens of Paleochorda call for no special mention, but the 
1 T regret to have overlooked Mr. B. N. Peach’s paper on Cyelus testudo, Carboni- 
ferous series, Langholm. (See Trans. Roy. Soc. Edinb. 1883, vol. xxx. pl. xxviii. 
figs. 9-9d, p, 227.—H.W. 
