U. S. NATIONAL MUSEUM 



BULLETIN 181 PLATE 13 



19 



20 



21 



10 



13 



11 



w 



14 



l.j 



22 



28 





^1 



30 



Jl 



37 



40 



38 





41 



16 



17 



18 



31 



"^^ll^ 



32 



33 



36 ' 



39 



42 



Cyclophorid mollusks of America. 



FOR EXPLANATION OF PLATE SEE PAGES 285. 286. 



