4 PROCEEDINGS OF THE NATION AI. MUSEUM vol 66 



from fine sandy clay, Rio Biiena Vista, just south of crossing of 

 Alazan to Moyutla road, Vera Cruz; fossil horizons 3 and 4; light 

 gray sandy clay, Rio Tuxpan, south side just above Agua Nacida, 

 Vera Cruz, all three lots collected by T. W. Vaughan. 

 This is the most delicate of the various species. 



EXPLANATION OF PLATES 



Plate 1 



Hantkenina alabamensis, new species 



Figs. 1-6. Side views of six specimens from Cocoa post office, Alabama. X 60 



Plate 2 



Fig. 1. Hantlcenina kocM Hantken. Side views and apertural view. (After 

 Hantken. ) 



2. Hantkenina mexicana, new species. Side view. X 75. 



3. Hantkenina brevispina, new species. Side view. X 75. 



4. Hantkenina longispina, new species. Side view. X 75. 



5. Hantkenina alabamensis, new species. Side view of Mexican specimen. 



X 75. 



o 



