124 EXPLANATION OF THE PLATES. 
Fic. 9,—PLEvROPHORUS COSsTATUS, Brown, sp. 
Arca costata, Brown, Trans. Manch., Geol. Soc., vol. i., p. 32, pl. vi, figs. 
3b4, 35. 
Pleurophorus. King, Permian Foss., p. 181, pl. xv., figs. 13—20. 
Original. Silksworth. Mus. G. S. I. 
Permian.—‘‘ This species appears to have had an extensive Geographical 
range. It is common at several localities in Durham, occurring also in 
the Permian Marls at Newtown, near Manchester,’’ King. Perm. Foss., 
p- 182. It is found also in Irish Permians, near Dungannon, Tyrone. 
GASTEROPODA. 
Fre. 10.—a, b, c. Turso Mancuntensis, Brown. 
Trans. Manch. Geol. Soc., vol. i., p. 63, pl. vi. figs. 1, 2,3. Perm. Foss. 
p. 205., pl. xvi., figs. 19, 20. 
a,b. Original. Back and front view; Tunstall Hill. Mus. G. S. I. 
e. Enlarged front view, from Perm. Foss., pl. xvi., fig. 20. 
Permian.—Shell Limestone, Tunstall Hill, Breccia, Black Hall Rocks: Mar/s, 
Newtown, near Manchester. 
Fie. 11—a, b. Prevrotomarta antrina, Schlotheim, sp. 
Trochilites antrinus. Schl. Akad. Minch., vol. vi., p. 32, pl. vil, fig. 6. 
Pleurotomaria antrina and P. Tunstallensis, King. Perm. Foss., pp. 215, 
216, pl. xvii., figs. 1—6. 
a. b, Front and back view. 6. Showing fissure, from Perm. Foss., pl. xvii., 
figs. 1, 2. Tunstall Hill. 
PrERMIAN.—Plentiful in shell limestone, at Tunstall and Silksworth, some- 
what rare at Humbleton, Castle Eden-Dene, and Dalton-le-Dale, in 
similar rock; very rare in the Breccia, Tynemouth-Castle, Cliff. King. 
Perm, Foss., p. 216. 
PISCES.—PLA COIDET. 
Fam.—PY CNODONTIDE. 
Fic. 12.—a, 6, c. PLaTysOMUS STRIATUS, Agassiz. 
Poiss. Foss., vol. ii., p. 168, pl. xvii, figs. 1—4. P. parvus, Ag. op. eit., 
p- 170, pl. xviii., fig. 3. King. Perm. Foss., p. 231, pl. xxvii, fig. 1 
pl. xxvill., fig. 1. 
a. Reduced to two-thirds of natural size, from Perm. Foss., pl. xvii. 
b, c. Scales from Poiss. Foss., pl. xvii., Marl-slate, Ferry Hill. 
PERMIAN Marl-slate, Ferry hill and Whitley ; Magnesian limestone, Low 
Pallion, Northumberland. 
