LOWER LUDLOW GROUP. 
165 


Case and 
Column of 
Drawers. 
Reference to McCoy’s 
Synopsis: and Figures of Genera. 
Names and References; Observations, &c. 

Ge3 
Ge3 



CRUSTACEA, 
Merostomata, Sub-Order Eurypterida. 
Pterygotus, (Agassiz), Huxley, Salter 
and Woodward. The giant of the 
Crustacea, attaining a size of seven 
to eight feet in length, and abund- 
ant in species. At first regarded 
as parts of a fish, it was soon re- 
stored to its true position by the 
renowned Agassiz, and it has since 
received attention from the above 
authors. (See Upper Ludlow.) 
Pterygotus? A thick anterior joint 
of some large species. (It can 
scarcely be the cup of a large cri- 
noid, much obliterated.) 
Pterygotus arcuatus, Salter (Mem. 
Geol. Surv. Mon. 1, on Pterygotus, 
p- 95, t. 13). The difference in 
sculpture and shape of the an- 
tenne marks this species from P. 
anglicus and its allies. 
Slimonia (Page, H. Woodward). 
[Slimonia differs from Pterygotus 
in shape and in the absence of the 
great chelate antenne. The tho- 
racic plate covering the sexual or- 
gans differs in male and female. | 
Slimonia punctata (Pterygotus, Sal- 
ter, Mem. Geol. Surv. Mon. 1, pl. 
10,11). A body-ring only. 
CRUSTACEA, Trilobita, Burm. 
Proetus latifrons, McCoy, sp. (Silur. 
Foss. Ireland, t. 4, fig. 11, Mem. 
Geol. Surv. Vol. 2, pt. 1, t. 6, fig. 1). 


Numbers and Localities. 

a. 521, Underbarrow, Ken- 
dal. 
b. 864, Leintwardine. 
b. 865, Leintwardine. 
a. 905, Underbarrow. 
