76 CARBONICOLA, ANTHRACOMYA, AND NAIADITES. 
Dimensions : 
Antero-posteriorly : : : . 20 mm. 
Dorso-ventrally 3 ; 
Locality.—Low-bottom Bed, Fulledge, Burnley. 
Observations—From the description and figures of de Ryckholt’s Cardinia 
angulata I am inclined to refer the British forms to his species, to which I consider 
Sir Wm. Dawson’s specimen of C. angulata from the South Joggins Coal-field 
also belongs, the specific name angulata having been given to it by him indepen- 
dently. I have therefore referred the specimens from Burnley to this species. 
The English examples, however, are somewhat larger. 
I have been able to examine very few specimens of this species, all of which 
are from Burnley; and I have not met with the form from any other British 
locality. 
It approaches somewhat the next species to be described, C. similis (Brown), 
in the possession of an oblique ridge and the compression above it; but the 
general shape and dimensions have made me hesitate to refer it to this species, 
and unfortunately at present no specimens have been found with the valves 
closed, so that the general shape of the united valves is not known. 
9 mm. 
14. Carponicona sImILis (Brown), 1843. Plate XI, figs. 6—13, 15, 17—23, 25—27. 
PacHYoDON sIMIniIs, Brown. Ann. and Mag. Nat. Hist., vol. xii, 1843, p. 393, pl. xvi, 
fig. 12. 
Unto simitis, Brown. Fossil Conchology, 1849, p. 178, pl. lxxii, fig. 9. 
Pacuyopon nanus, Brown. Ann. and Mag. Nat. Hist., vol. xii, 1843, p. 392, 
pl. xvi, fig. 1. 
Unto wanus, Brown. Fossil Conchology, 1849, p. 177, pl. lxxiii, fig. 7. 
Non Carpryta nana, de Koninck. Descript. Carbonif. Anim. Foss. Belgique, 1842, 
p- 71, pl. i, fig. 6. 
Specific Characters.—Shell almond-shaped, transversely oval, slightly oblique ; 
anterior end elliptically rounded; narrow dorso-ventrally. Inferior border 
regularly convex, not interrupted by a sinus. Posterior end deeper than the 
anterior, and bluntly rounded in old specimens; but in young forms it is obliquely 
truncate from above downwards, with a somewhat acute posterior inferior angle. 
The superior and inferior borders are subparallel. 
The umbones are moderately convex, flattened, elongated, low, and contiguous ; 
situated about the junction of the anterior and middle thirds of the shell. They 
are continued downwards posteriorly to the posterior-inferior angle by a ridge, 
above which the shell is rapidly compressed into the superior and posterior 
