U. S. NATIONAL MUSEUM 



PROCEEDINGS, VOL. 86 PLATE 21 



1, OpercuUnoides ntimmulitiformis (Rutten), Tantoyuca formation, collection P. von Schumacher no. 2412, east 

 of Tempoal, Veracruz; 2, 0. prenunimulitiformis, new species, Guayabal formation, well sample, Poza Rica 

 no. 8; 3, 0. ocalanus (Cushman) minor, new variety, Guayabal formation, collection P. von Schumacher no. 

 2589, east of Tempoal; 4, tOperculinoides sp., Tantoyuca formation, collection H. Meyer no. 1471, near Los 

 Aj'os, Santa Clara, southeast of Tantoyuca: 5, OpercuUnoides sp. B, Guayabal formation, collection H. E. 

 Rankin no. 277, near Tantoyuca; 6, OpercuUnoides sp. A, Tantoyuca formation, collection P. von Schumacher 

 no. 1624, east of Tempoal; 7, 8, 0. catenula (Cushman and Jarvis), lower part of Chicontepec formation, near 

 Sabaneta, collection W. Tappolet no. 1848, X27; 9, O.jennyi, new species, Guayabal formation (Temporal of 

 ver Wiebe and Muir), near Sabaneta, collection H. Jenny no. 1573; 10, 11, 0. anti^uensis V'aughan and Cole, 

 Meson formation, bluff below Tampico Country Club, Tampico, Tamaulipas; 12, i'C. dickersoni Palmer, Car- 

 denas beds (Upper Cretaceous), Cardenas, San Luis Potosi, X42; 13, 0. zuillcoxii (Heilprin), Tantoyuca type 

 locality, near Tantoyuca on road to Chopopo, Veracruz. All figures except figs. 7, 8, and 12 X20. 



