-T' 



MANUAL 



OP 



T 



Structural and Systematic. 



WITH ILLUSTRATIONS OF THE SPECIES. 



By GEORGE W. TRYON, jR. 



Conservator of tiik C<)N( iioLoiacAL Suction of the Academy of Natural Sciences 



(IF I'Jin.ADELPlIIA. 



VOL. IX. 



SOLARIID.E, IANTHINID.E, TRICHOTROPID^, SCALARIID^, 

 CERITHIID.E, RISSOID.E, LITTORINID.E. 



PHILADELPHIA: 

 Published by th.e Antlior, 



Academy of Natural Sciences, Cor. 19th & Race Sts. 



1887. 



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