^'o. 478] ODONTOPHOh'M. APPARATI S /.V sycoTyi'Cs 711 



Loisel ('92) describes the apparatus as foim,! in Hch'x, an<] (rives 

 a rather confused account of its action. 



Oswahl, in 1<S93, published quite a .h-tailcd ac.ouni of the 

 "Riisselapparat" of tlie Prosobranchs, deahnu' csprciallv with the 

 apparatus as found in Hiicciinim undatuiii. He .hvscrilK's at hMi<rth 

 the muscles that conti-ol the movemeiit of the rachihi. as well as 



rext-li-uiv.. .cheniala' d luo plaf^ ' Ilr aUo ,on^idr,. d,r 



and I filid he su^ro-osted in a nund)er'of cases the very nonlencla- 



vations had been made before the literature of the subject became 



In reo-anl to the ra.pitm a-ti.-n of the raduia. u h.-iher it i^ a. .-om- 

 plished by the hckiii- :irfioi, of the . artiia-e or hv active to and fro 



