642 MEMOIRS OF THE CARNEGIE MUSEUM. 



EXPLANATION OF PLATE XXXIV. 



Shells of Diplodon hasemani Ortmann and Diplodon imitator Ortmann. 



All figures natural size. 



Figs. 1-4. Diplodon hasemani Ortmann, from Rio Guapore, near Rio Sao Simao, 

 Matto Gtosso, Brazil. Carn. Mus. Cat. No. GL5857. 



Fig. la. Adult male (No. 10), lateral view. 



Fig. 16. Adult male (No. 10), dorsal view. 



Fig. 2a. Adult, gravid female (No. 9), lateral view. 



Fig. 2b. Adult, gravid female (No. 9), inner view of left valve. 



Fig. 2c. Adult, gravid female (No. 9), inner view of right valve. 



Fig. 3. Half-grown, gravid female (No. 4), lateral view. 



Fig 4. Young, gravid female (No. x), lateral view. 



Figs. 5-7. Diplodon imitator Ortmann, from Rio Vaccahy-mirim, Santa Maria, 

 Rio Grande do Sul, Brazil. Carn. Mus. Cat. No. 61.924S. (See also PI. XXXV, figs. 1 

 and 2). 



Fig. 5a. Half-grown male (No. 29), lateral view. 



Fig. 56. Half-grown male (No. 29), inner view of left valve. 



Fig. 5c. Half-grown male (No. 29), inner view of right valve. 



Fig. 5d. Half-grown male (No. 29), dorsal view. 



Fig. 6a. Young male (No. 14), lateral view. 



Fig. 66. Young male (No. 14), dorsal view. 



Fig. 7a. Adult female (No. 33), inner view of left valve (see also PI. XXXV, fig. 1). 



Fig. 76. Adult female (No. 33), inner view of right valve. 



