30 BULLETIN OF THE 



Mr. Walcott's note on the type of Stenotheca pauper recalls this variety ; bnt 

 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 ciirvirostra, 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 striae are fine and closely set. Diameter of the 

 aperture of the shell in the largest specimen found, 4 mm. ; height of the 

 shell 5 mm. 



Locality and position. — Station No. 2, North Attleborough, Mass., Cam- 

 brian, 5 specimens. 



9. Platyceras primaevum, Billings. 



Plates I. and II. Fig. 10. 



Shell very small, whorls two in number. Seen from above, the whorls Ue 

 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 striae ; 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 Ls 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 



