peesident's addeess. 



67 



we reconstruct a phylogenetic tree, taking as our basis the one by the 

 same author in Blanchard's " Traite cle Zoologie," fasc. xvi {38, p. 176), 

 but correcting it to his later views and inserting, for reasons hereafter 

 to be explained, the additional group-names " Prostreptoneura " and 

 " Conularida," the following diagrammatic scheme results :— 



Pulmoaata. 



Nudibninchia. 



Septibranchia. 



Teutibiaucliia 



Octopoda 



Eulamellibrancbia. 



Myopsida. 



FLlibranchia. 



Protobrancbia. 



Pectinibranchia. 



[Euthyneura.] 



[SCAPHOPODA.] 



AspidobraQchia. 

 Prostreptoneura. 

 [Gastropoda.] 



[Pelecypoda.] 



[ProrKipidoglossa.] 



Polyplacbpbora 



[Amphineura.] 



Aplacopbora. 



i [POLYCH.^TA 



'^( Errantia.] 



TABLE I. 



