~T 
Or 
EXPLANATION OF THE PLATES. 
Lupiow. Sil., 4th edition, p. 528. ‘ Very abundant in the greenish Up- 
per Ludlow quartzites of Benson Knot, Kendal, Westmoreland.” Brit. 
Pal. Foss., p. 258. 
Fig. 4.—PTERINEA RETROFLEXA, Wahlenberg, sp. 
Avicula, Sil. Syst., p. 609, pl. v., fig. 9. Pterinea, Sil., 4th edition, p. 529. 
Origina!l.? Ludlow rocks, Clogher, Dingle, Co. Kerry. 
LLANDOVERY TO LupLow.—Sil., 4th edition, p. 529. “In the Llandovery 
rocks of Malvern, a variety of this species is plentiful, also in the Conne- 
mara tract of Galway ;” ibid., p. 211. It is also an abundant species in 
the Wenlock limestone ;” ibid., p. 121, and has been found in Wenlock 
rocks, North Wales. Mem. Geol. Surv., vol. iii., pp. 278-9; and in the 
Upper Ludlow of the Malverns, and Kendal, in Westmoreland. Prof. 
Phillips records its occurrence in the Malvern, Abberley, Woolhope, 
May Hill, Usk, Builth, Llandeilo, and Marloes Districts. Mem. Geol. 
Surv., vol. ii., pt. i., p. 271. In Ireland it is not unfrequent in Wen- 
lock and Ludlow rocks of the Dingle Promontory, Co. Kerry. 
Fic. 5.—CARDIOLA INTERRUPTA, Sowerby. 
Sil. Syst., p. 617, pl. viii., fig. 5. 
Original, Lower Ludlow, Vinnal Hill, Ludlow. Mus, G. S. I. 
Carapoc, WENLOCK, AND LupLow.—Sil., 4th edition, p. 529. “ The most 
common of the Lamellibranchiate shells, in the Lower Ludlow; this 
species, formerly believed to be peculiar to this zone, has also been found 
in the Caradoc formation ;” ibid., p. 127. It is recorded from Abberley, 
Malvern, Woolhope, Usk, and Builth Districts, in Wenlock limestone, 
Lower Ludlow, Aymestry limestone, and Upper Ludlow. Mem. Geol. 
Surv., vol ii., pt. i., p. 265. In Wenlock rocks, near Llansannan, &c., 
North Wales, at several localities. Mem. Geol. Surv., vol., iii., 
pp- 278-9. Lower Ludlow, Aymestry ; Breidden Hills; Radnor Forest, 
&e. Sil. Syst., p. 617. In Ireland it has been collected by the Geol. 
Survey, from Derrymore Glen, Co. Kerry. 
Fic. 6.—?CARpDIOLA sTRIATA, Sowerby, sp. 
Cardium? Sil. Syst., p. 614, pl. vi, fig. 2. Cardiola? Sil., 4th edition, 
p- 529. 
Original. Reduced to half natural size. Lower Ludlow, Leintwardine. 
Mus. G. S. I. 
WEN Lock and LupLow.—Sil., 4th edition, p. 529. “+ Equally characteris- 
tic with the preceding species, and as yet known only in Upper Silurian 
rocks. It is found in all the fossil-bearing localities of Shropshire 
and the neighbouring regions;” ibid., p. 127. It occurs in Aymestry 
damestone, Aymestry, and in Lower Ludlow, near Shelderton. Sil. Syst., 
p- 614. It is recorded as occurring in Aymestry limestone and Upper 
Ludlow rocks in the Malvern, Woolhope, and Usk Districts. Mem. Geol. 
Surv., vol. ii., pt. i., p. 265. 
