PLATE IX. 
SILURIAN SPECIES. 
Fie. 
1—6. Spirifera plicatela, var. radiata, Sow. 1. After original figure (‘ Sil. Syst.,’ pl. 12. 
fig. 6.) Wenlock Limestone, Malvern Hills. Mus. 
Geological Society, London. Fig. 2, a large example, 
Dudley. Collection of Mr. Fletcher. Fig. 2.4, portion 
of shell, considerably magnified. Figs. 3, 4, 5, small 
examples ; same locality. Fig. 6, interior of ventral 
valve. 
7—8. A; es var. globosa, Salter. Fig. 7, avery large example from Wenlock 
Limestone, Dudley Collection of Mr. Fletcher. Fig. 8, 
same locality. 
9—12. ui ie Linneus, sp.=Spirifer interlineatus, Sow. Delthyris cyrtena, 
Dal., His.) &e:. Fig. 9, after ‘onginal figure of Sp. 
interlineatus, Sow. (‘ Sil. Syst.’ pl. vi, fig. 6.) Aymestry 
Limestone, Aymestry, &. Mus. Geol. Soc., London. 
Fig. 10, from Wenlock Limestone, Benthall Edge. Col- 
lection of Dr. Holl. Fig. 11, Wenlock Shale, near 
Dudley. Fig. 12, Wenlock Limestone, May Hill. 
Mus. Geol. Soc., London. 
13—24. Cyrtia eaporrecta, Wahl., sp.= C. trapezoidalis, His. Figs. 13—17, different 
shapes from Wenlock Limestone, Dudley. Fig. 18, 
Lower Ludlow, Dog Hill, Ledbury. Mus. Geol. Survey, 
London. Figs. 19—21, enlarged deltidiums, to show 
their peculiar shape, and circular foramen, when it exists. 
Fig. 24, mternal casts of dorsal valve from Ludlow 
Shales, Pentland Hills. Fig. 22, internal cast of ventral 
valve; fig. 22a, enlarged. Same locality and Col- 
lection. Fig. 23, another internal cast of same valve, 
showing the wide triangular area. Ludlow Shale, Pent- 
land Hills. Collection of Mr. D. J. Brown. 
