NATICA or the naticoici type holds a unique place in the ontogeny and phylogeny of the coiled Gastropoda. Its position in the history of the race has been admirably pointed out by Grabau1 in his " Studies of Gastropocla," and in his treatise on the "Phylogeny of Fusus and Its Allies. "9 There would be little cause at this time to take up the discussion again, if it were not for the fact that certain new data pertaining to the development of some Paleozoic, Mesozoic, Cenozoic and Recent forms have been observed. The basis for classification as presented by Dall,3 iUlrich,' Grabau5 and others will probably always be argued pro and con, depending upon the point of view of the zoological systemiatist at the time he makes a study of the living forms. His material for study consists or should consist of the entire living organismi; consequently he is able to trace the ontogeny of an individual in detail. But, to the paleontologist, who is dependent upon the shell of the fossil gastropod for his study, the emphasis is placed on the shell development as a means of formulating a natural classification. The fundamental law governing the development of races was briefly stated by Alpheus Hyatt, "Ontogeny recapitulates phylogeny. " This, to Hyatt, was not a new concept, for Louis Agassiz, in 1847, stated, "The Lord brings back in the young those types that have gone be-