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Fig. 



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9 a 



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12. 



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 KiSmondii. Natural size. 3 



Clatella gravida. Natural size. 4 



C. sinuata. Natural size. 5 



Pleurotoma Carpenteriana. Natural size. 5 



P. Trtoniana. Natural size. 6 



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



P. (Surcula) perversa. Natural size. 6 



S. Voyi. Natural size. 7 



Clathttrella Conradia.va. Mae-nified. 7 



