56. Cyreua maritima, Adams. P 



57. Cyrena mexicana, Sowb. 



58. Cyrena moreauensis, Meek §• 



Hayden. 



59. Cyrena nebraskensis, Pr. F. 



60. Cyrena occidentalis, Meek ^• 



Haijden. I 

 CI. Cyrena olivacea, Cpr. C. A. 

 62. Cyrena panamensis, Pr. C. A. 



F. 



63. 

 64. 

 65. 

 66. 



67. 

 68. 

 69. 



Cyrena placens, Ilanley. C. A. 

 Cyrena radiata, Hanlej/. C. A. 

 Cyrena salmacida, Morelet. C. A 

 Cyrena sordida, Hanley. C. A. 



Corbicula convexa, Desh. C. A 

 Corbicula truncata, Pr. F. 

 Corbicula ventricosa, Pr iS. 



(5) 



