30 BULLETIN OF THE 
Mr. Walcott’s note on the type of Stenotheca pauper recalls this variety ; but 
our specimens are larger than is indicated by the original description of Bil- 
lings, and the apex can scarcely be said to be incurved. The ridges are coarse, 
and not small. 
Locality and position. — Stations No. 2 and 3, North Attleborough, Mass., 
Cambrian, 30 specimens; also at Troy, N. Y., and Bic Harbor, Canada? Va- 
rieties pauper and abrupta are not found connected by intermediate forms at 
North Attleborough, and may be distinct species. 
8. Stenotheca curvirostra, sp. n. 
Plate I. Fig. 8. 
Shell small, rather elongate; the lower part gently curved, the curvature 
more marked, especially at the beak; the beak always considerably elevated 
above the aperture of the shell. The transverse ribs are narrow and sharp; 
from ten to eighteen are found on a single shell; the interspaces are broad 
and flat. The longitudinal strie are fine and closely set. Diameter of the 
aperture of the shell in the largest specimen found, 4mm.; height of the 
shell 5mm. 
Locality and position. — Station No. 2, North Attleborough, Mass., Cam- 
brian, 5 specimens. 
9. Platyceras primevum, Billings. 
Plates I. and II. Fig. 10. 
Shell very small, whorls two in number. Seen from above, the whorls lie 
very nearly in the same plane; they increase rapidly in size, the second be- 
coming comparatively very large, and all being throughout evenly rounded. 
Seen from below, only the last whorl is visible, and the whorls have a some- 
what spiral form; the ascent of the spire increases rapidly towards the aper- 
ture, at that point partly overlapping the first part of the whorl. There are 
faint traces of transverse strie; this characteristic ornamentation of the 
species would not be well preserved in the decomposed material in which 
the North Attleborough specimens occur. Width of the shell 2.8 mm.; height, 
1.5 mm. 
Locality and position. — Station No. 2, North Attleborough, Mass., Cam- 
brian, a dozen specimens; also at Troy, N. Y., and Bic Harbor, Canada. 
10. Pleurotomaria (Raphistoma) Attleborensis, sp. n. 
Plate II. Fig. 11. 
Shell small, flattened, composed of three whorls. The first whorl is very 
small; the succeeding ones increase rapidly in size. The surface in general 
slopes at a low angle from the apex of the shell to the sides. In the last whorl 
o 
