SHELLS OF THE LOWER LUDLOW ROCK. 



617 



Many individuals of this shell, too imperfect to be described, are imbedded in the matrix which 



filled the interior of a Phragmoceras and are accompanied by a coralline. Little more than 



the surfaces by which they were attached is distinguishable, and viewing them thus, the whorls 



appear to be sinistral. The name expresses the thinness of the shell. 



Loc. Leintwardine near Ludlow. 

 Cypricardia solenoides, PI. 8. f. 2. Subcylindrical, a little compressed ; beaks near to the small, 



rounded, anterior extremity ; posterior extremity flattened and truncated at the edge ; lunette 



large and deep. Length 5 A lines, width 111 lines. 



Some specimens of C. amygdalina approach near to this species, but the fossils referred to 



this genus throughout the Upper Silurian Rocks are often so much distorted by pressure that 



it is difficult to distinguish their original form. 



Loc. Ludlow escarpments ; Abberley. 

 Psammohia rigida, PI. 8. f. 3. Subcylindrical, three times as wide as long ; surface raised in 10 



or 12 sharp undulations; anterior side slightly attenuated; the posterior truncated; beaks 



rather nearest to the former ; base straight. Length 3± lines, width about 9 lines. 



A small shell, the specimen is not perfect, but shows indications of 3 ridges diverging from 



the beaks over the posterior side. 



Loc. Garden House near Aymestry. 

 Cardium striatum. (See PL 6. f. 2.) Also Aymestry Limestone. 



Loc. Shelderton. 



Cardiola [Broderip). Gen. Char. "An oblique, equal- valved, unequal- sided bivalve; beaks 

 prominent and curved; surface concentrically furrowed ; hinge line long, with a flat area." 



Not being able to refer the two following fossils to any established genus, Mr. Broderip pro- 

 posed a new one for them. He has not, however, had access to those parts which are required 

 for clear generic distinctions, and was obliged to confine himself to an indication of the general 

 contour. These shells are very characteristic of the lower members of the Upper Silurian 

 Rocks over very wide tracts. 

 Cardiola fibrosa, PI. 8. f. 4. Cordiform, longitudinally striated; striae numerous, fine; beaks 

 elongated, sharp ; concentric furrows about 9. Length 11 lines, width about 10 lines. 



The absence of the longitudinal striae upon the zones near the beak may be due to the fossils 

 being casts of the internal surface of the shell. 



Loc. Mary Knoll Dingle, near Ludlow ; Long Mountain, near Welch Pool; Flagstone 

 Quarries of Yechad, Montgomeryshire ; Radnor Forest, Sfc. 

 Cardiola interrupta, PI. 8. f. 5. [Cardium cornu- copies^ , Goldfuss, t. 143. f. 1.) Cordato-ovate, 

 rather compressed ; surface marked with many diverging furrows which are not so deep as 

 the less numerous concentric ones ; beaks short. Length 11 lines, width the same. 

 Loc. Garden House Quarry near Aymestry ; Breidden Hills j Long Mountain and Railth 

 near Welch Pool; Water-break-its-neck, Radnor Forest ; Cwm-craig-dhu, Mynidd- 

 epynt, Brecknockshire. 



Modiola ? semisulcata, PI. 8. f. 6. Transversely ovate, convex, imperfectly 2 lobed; anterior lobe 



1 The Cardium cornu-copice, Goldfuss, is the Cardiola interrupta of the Lower Ludlow. Our name was 

 adopted and printed (see Geol. Proc. vol. ii. p. 13. Jan. 1834.) four years before the last fasciculus of the work 

 of Goldfuss was published. Although describing it as a Cardium, Goldfuss allows that he lefers it with un- 

 certainty to that genus. — R. I. M. 



