PURPURA. MONOCEROS. CONCHOLEPAS. 105 



P. NUCLEUS. Sinall^ ovate^ shining, smooth, 

 but transversely striated near the lip and at the 

 base; brownish chestnut; aperture rounded; lip 

 striated within, i- W. 23. 91. 



MONOCEROS. 



Shell oval; aperture longitudinal, terminating in- 

 feriorly by an oblique sinus; a conic tooth at 

 the base of the lip internally, 



M. ciNGu LATUM. Ovate-obloug, contabu- 

 lated, whitish^ covered with a reddish epidermis, 

 and adorned with smooth black belts and fine 

 transverse striae ; whorls angulated above ; aper- 

 ture very white. 1 1. W. 24. 168. 



M. iMBRiCATUM. Ovatc-ventricose, roughish, 

 ash-colour or reddish grey, with very crowded 

 transverse imbricated scaly ribs ; whorls rounded; 

 spire short ; lip crenulated. 2. W. 22. 54. 



M. CRASsiLABRUM. Ovate, thick, smooth, 

 reddish ash-colour ; whorls convex ; spire rather 

 exserted; lip exceedingly thick, almost double, 

 toothed within; horn short, obtuse. 1^. E. 

 396. 2. 



CONCHOLEPAS. 



Oval, inflated, semi-spiral; summit inclined obliquely 

 towards the left margin ; aperture ample, lo7i- 

 gitudinal, oblique, with a slight notch at the 

 f2 



