FIG. S. Atlanta Peronii (after Gegenbaur). a, Pharynx ; b, buccal ganglion ; c, tentacle ; d, 

 eye ; e, cerebral ganglion ; /, aorta cephalica ; [/, pleuro-visceral connective ; h, columellar muscle ; 

 i, fc, osphradiuni ; /, vagina ; m, ctenidium ; n, anus ; o, uterus ; p, nephridium ; q, aorta cephalica ; 

 r, auricle ; s, ventricle ; t, aorta visceralis ; u, digestive gland (liver) ; v, ovary ; w, stomach ; x, 

 pedal ganglion ; y, operculum ; 2, metapodium ; 1, sucker of the fin-like foot (rudimentary sole) ; 2, 

 foot ; 3, auditory organ ; 4, oesophagus ; 5, snout ; 6, salivary gland. 



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FIG. 9. Pterotrachea (Firola) coronata (after Leuckart). a, Pharynx; b, proboscidal snout ; 

 c, eye ; d, cerebral ganglion ; e, pedal ganglion ; /, pedal artery ; g, intestinal canal ; h, pleuro- 

 visceral connective ; i, parieto-visceral ganglion ; t, osphradium ; 7, ventricle ; m, auricle ; ?z, 

 anus ; o, ctenidium ; p, metapodium ; q, appendage ; r, aorta cephalica ; 5, nerve running to the 

 metapodium ; f, artery ; n, foot ; r, common pedal artery ; u% cephalic artery ; a-, auditory organ ; 

 y, buccal ganglion. 



