583 



Discohelix Dunker 1849. 



3Iuf ein Orbis fel^r ä^ntii^eö ©el^äufe aitC bem ßiaö 

 Begrünbet. — CJP^iliV^pi ^anbbiid^ pag. 500) 

 Discohelix Diinker 1849. 



D. lesta discoidea, compressa, utrinque plano-con- 

 cava, calculiformij anfraclibus 4 — 5 quadrangulis, haud 

 involulis, apertura quadrato-subcuneata. — (Dunker 

 in Palaeonlographica I pag. 132.) 

 Discohelix Duuker. 



Shell Discoidal, greatly depressed, nearly foli- 

 aceus, whorls very numerous on the same plane, roun- 

 ded or carinaled at the periphery, tho last not dela- 

 ched, aperlure wide, Iransverse. 



Synonyme: Orbis Lea, — Ex. Discohelix foliacea Phil. 



We have been obliged to change the name of 

 this genus, as Orbis is already in use as a synonyme 

 of Planorbis and is also employed for a genus of fishes. 

 A living example has been recorded by Philippi as 

 exisling in the Mediterranean; the other species are 

 eoeene fossils from Alabama (H. & A. Adams pag. 244.) 



3J2an fiet;t l^ierau^, bag $^i(i|}))t bei ber Untevfud;ung 

 feiner ftclüani[(^en %xi bie (Gattung Planaria entiüeber 

 jufäüig iibev[a^ ober a'6fid;t(i(^ nid;t Beachtete, ^o Um 

 er baj«, feine Irt in bie Gattung Orbis iw fteüeu, ipä^* 

 veub bod;, ipie (c^on oben angeführt, Sea l>orfid;ti3 unb 

 abfid^tüd; bie geÜelte Orbis »on ber gevunbeten Planaria 

 fc?()eibet. 5lbam§ fd;riekn, o^ne i\x t»erg(eid;en, $t;i(i):pl 

 itac^, uub tDaveu ba^ev ge^tüungen, eine ©attungßbiagnofe 

 SU faBri^ireu, bie auf alle beibe ^a§te. 3n i^rem ßifer, 

 €i)nom}me ju termeibeU; !amen fie nun gar baju, für 



