Fie. 
PLATE VI. 
SILURIAN SPECIES. es 
1—4. Discina striata, Sow. Fig. 1, after original figure (‘ Sil. Syst.,’ pl. v, fig. 11), 
6, 
CO 
9) 
> 
Upper Ludlow, Delbury, Shropshire; Mus. Geol. Soc. Fig. 
2, a large specimen from Upper Ludlow, Whitecliff, near 
Ludlow. Collection of Mr. Marston. Fig. 3, Murchison’s 
original specimen (fig. 1). ['The strize are so fine and close 
on the specimen, that they can hardly be detected with 
the naked eye, and are, consequently, too large on the figure. 
The enlarged fig. 3 @ shows them better.] Fig. 4, an elon- 
gated example ; Upper Ludlow, Whitecliff. Collection of Mr. 
Lightbody. 
Verneulu, Dav. Original specimen, from Wenlock limestone, Stoney 
Mill, near Ledbury. Sharpe’s collection, Mus. Geol. Soc. 
crassa, Hall. P Fig. 6, from Llandeilo flags, Builth. Fig. 7, from 
Penwhapple Glen, Ayrshire. Both in the Mus. Geol. Survey, 
London. 
(Lrematis) Siluriana, Dav. Fig. 8, natural size ; Caradoc beds, Horderley. 
(This beautiful specimen was presented to the Mus. Geol. 
Survey, London, by Mr. E. H. Birkenhead.) Fig. 8a, a 
considerably enlarged figure of the free or upper valve. Fig. 
8 6, a portion of the shell still more enlarged so as to show 
better the character of the sculpture. mi 
(Zrematis) punctata, Sow. Fig. 9, natural size, from Caradoc sandstone, 
Cheney Longville Lane, Shropshire; Mus. Geol. Survey, 
London. Figs. 9a and 6, considerably magnified illustra- 
tions in which the shell-sculpture has been carefully com- 
pleted from perfect portions visible here and there on a 
specimen from the Caradoc beds of Hope Bowdler, near 
Church Stretton, Shropshire, in Museum Geol. Survey, 
London; and from another example in the Collection of 
Mr. Lightbody. Fig. 9¢ shows the sculpture still more 
enlarged. 
