Chap. VIII. 
UPPER SILURIAN IN SCOTLAND. 
161 
* Such as Apus and Nebalia. 
t See Pal. Foss. Woodw. Mus. PI. I. e. fig. 7 ; 
Quart. Journ. G-eol. Soc. vol. ix. p. 13; and infra, 
p. 238, for a proof of Prof. M'Coy's acumen in 
from any of the forms known on the 
same horizon in England. 
The near alliance of these large 
Crustacea to some of the minuter 
recent forms has been fully explained 
by Professor Huxley in the memoir 
above mentioned, and will be touched 
upon in the Chapter on Organic 
Kemains. The number of species 
must have been very great, more 
than twenty being known in Bri- 
tain. 
With them are associated, not only 
in Lanarkshire, but in Shropshire and 
"Westmoreland, other, very curious, 
shrimp-like animals, apparently al- 
lied to the Phyllopodous Crustacea of 
the present day *. They have been 
called Ceratiocaris by Prof. M'Coy ; 
and the fine specimens collected in 
the South of Scotland and other lo- 
calities have clearly shown that to 
this genus must also be referred those 
singular spine-like prongs which the 
same author described under the 
name of Leptocheles. A figure of 
the genus, as restored, was given in 
the Quart. Journ.Geol. Soc. for 1856, 
vol. xii. p. 33 ; and the fossil will be 
figured in Chapter X.f 
The reader who refers back to the 
figure of Hymenocaris vermicauda of 
the Lingula-flags (p. 44), will see 
that animals of the same general 
form were in existence in the earliest 
time of the Silurian epoch. 
Fragments of large Crustaceans of 
the group of Eurypterida $ (Bur- 
meister), to which the Pterygotus be- 
longs, have also been found in the 
' Tilestones ' of Westmoreland ; and 
distinguishing some of these Crustaceans from the 
defences of Fish. 
J See Palseoz. Fossils, Woodwardian Museum,. 
Fasc. 1. 
M 
