NO. 1 



SOOT-RYEN : THE FAMILY MYTILIDAE 



35 



Fig. 17. Aulacomya atcr (Molina). Oflr Middle Chincha Island, 



Peru. Posterior part of mantle. 

 Fig. 18. Aulacomya ater (Molina). Off Middle Chincha Island, 



Peru. Posterior part of mantle with dorsal opening seen 



from behind. 



Fig. 19. Ischadium recurvus (Rafinesque). Santa Rosa Sound, 



Florida. No anterior adductor, broadly united posterior 



retractors and posterior adductor. 

 Fig. 20. Ischadium recurvus (Rafinesque). Santa Rosa Sound, 



Florida. Posterior part of mantle seen from behind, with 



long median flap of the septum. 



