PLATE I. 



PAGE 



Cancer Brewerii. Natural size. 1 



Triptera clavata. 



Two views, magnified to show front and lateral outlines. 1 



Trophon ponderosum. Natural size. 2 



Chrysodomus recurva. Natural size. 3 



? Metula Remondii. Natural size. 3 



Clavella gravida. Natural size. 4 



C. sinuata. Natural size. 5 



Pleurotoma Carpenteriana. Natural size. 5 



P. Trtoniana. Natural size. 6 



Restored outline of outer lip, from the lines of growth. 



P. (Surcula) perversa. Natural size. 6 



S. Voyi. Natural size. 7 



Clathurella Conradiana. Magnified. 7 



