LOWER HELDERBERG ROCKS. 
347 
PTEROPODAH]. 
The strata of the Lower Helderberg group have furnished two species of 
Conularia which appear to be distinct from any in the preceding forma¬ 
tions. The Conularia, however, like all the phosphatic fossils, offer so 
little variety of form and surface ornament that the different species are 
not readily distinguished*. 
Conularia pyramidalis (n. s.). * 
Plate LXII A. Fig. 1 a - d. 
Shell pyramidal, quadrangular, length about two and a half to three times 
the width at the base ; apex rounded, smooth ; sides a little convex ; 
sulci at the angles narrow, abrupt, a faint longitudinal depression along 
the middle of each side; transverse ridges bending upwards towards 
the angles, very slightly near the base and more abruptly towards the 
apex, continuous across each face, being slightly depressed in the 
middle, and meeting at the longitudinal suture at about the same angle 
as in the middle of each side; about fifteen or sixteen in the space of 
three lines, sometimes more crowded at intervals near the base ; inter¬ 
mediate spaces marked by longitudinal striae, of which there are more 
than twice as many, in an equal space, as of the transverse ridges : 
crests of the transverse ridges marked by short nodes or granules at 
the junction of the longitudinal striae. 
This species resembles the C. trentonensis in general form; but the transverse 
ridges and longitudinal striae are generally finer in that species, which, however, 
presents considerable variation in these characters. 
Notwithstanding that several of the specimens are broken across, they do not 
show any septa or other internal divisions; and the two specimens from the Trenton 
* That the phosphatic shells exhibit so little variety, compared with the calcareous shells, is a fact that 
presents an interesting analogy to the few modifications of mineral forms in the phosphates, and the great 
multiplicity of form in the carbonates, of lime. 
