610 



SHELLS OF THE UPPER LUDLOW ROCK. 



Semicircular, two-lobed, oblique, rather convex, transversely wrinkled ; anterior lobe very 

 small. Length 10 lines, width If inch. 



Hisinger refers this species to the lias and lower oolite. If this be correct, our species 

 cannot be the same as that of Hisinger. 

 Loc. Hale End, Malverns ; and near Usk. 

 Avicula Uneata, f. 10. Obliquely ovate, flattened, ornamented with many radiating elevated lines ; 

 anterior lobe minute, the posterior ear distinct, triangular, half as long as the posterior slope. 

 Length 9 lines, width 1 inch 2 lines. 

 Loc. Ludlow. 



Orbicula rugata, f . 1 1 . Nearly orbicular ; upper valve a very low oblique cone with a concen- 

 trically wrinkled surface j lower valve nearly flat. Diameter 6 lines, height 2 lines. 

 Loc. Ludlow promontory, viz. Richards Castle, 8rc. ; Delbury ; Bradnor Hill, Kington ; 



Bagbarroiv Hill ; Pains Castle, Radnorshire. Very abundant. 

 Orbicula striata, f. 12. Orbicular, convex, covered with minutely radiating stria? ; apex deflected, 

 marginal. Diameter 7 lines, height 3 lines. 



One specimen is attached to the septum of an Orthoceras. 

 Loc. Delbury, and Ludlow Hills. 

 *Leptcena lata, f. 13. {Von Buch; Producta, Sow.) Semicircular, the front rather straight; 

 upper valve convex, the middle a little depressed ; lower one concave ; surface covered with 

 fine radiating ridges ; hinge line straight, furnished with 8 or 10 long divaricating spines. 

 Length half the breadth. 



The spines in all the specimens we have seen are simple tubes, not jointed as they are figured 

 and described by Baron Von Buch, who must have had much better specimens than occur in 

 England. 



Loc. Ludlow promontory ; Delbury, and the range of Mogg Forest, Munslow, 8$c; 

 Presteign ; Stoke Edith ; Fownhope, and outer band of Woolhope Valley ; Bradnor 

 Hill; near Kington; near Usk; Bagbarroiv Hill; North of Barrow; near Newn- 

 ham ; in the Brecon anticlinal. Characteristic and most abundant. 



Atrypa didyma, Dalm. (See PI. 6. f. 4.) Also Aymestry Limestone. 

 Loc. Fownhope ; Dog Hill, Ledbury. 



Atrypa affinis. (Min. Conch, t. 324. f. 2.) (See PI. 6. f. 5.) Also in Aymestry Limestone and 

 throughout the Upper Silurian Rocks. 

 Loc. Ludlow ; Aymestry, and many localities. 



Spirifer crispus. (See PI. 12. f. 8.) Also Wenlock Limestone. 

 Loc. Abberley ; Freshwater east, Pembrokeshire. 



* Spirifer ptychodes. (Delthyris ptychodes, Dalm. Act. Holm. 1827- p. 124. t. iii. f. 5. ; Hisinger 

 Petr. Suec. p. 73. t. xxi. f. 8.) (See PI. 3. f. 13.) Also Old Red Sandstone. 

 Loc. Abberley; Bradnor Hill ; near Kington; Fownhope. 



Spirifer trapezoidalis, f. 14. ( Cyrtia trapezoidalis, Dalm. Act. Holm. 1827. p. 119. t. cxi. f. 2; 

 His. Pet. Suec. p. 72. t. xxi. f. 1; Von Buch. PL 1. f. 15 and 16.) Nearly semicircular, 

 transverse longitudinally striated : a rounded elevated ridge extends from the beak to the front 

 of the upper valve with a corresponding furrow in the other valve; hinge line rather shorter than 

 the diameter of the shell, the extremities rounded ; area large, curved ; the foramen narrow, 

 Loc. Usk ; Craig~y-garcyd. {Iron Bridge, Coalbrook dale, V m Buch.) 



