SPECIES OF CAMERINIDAE — BARKER 317 



Test complanate, much compressed, composed of 2 to 21/2 whorls, 

 the final whorl opening into a broad flange occupying the greater 

 part of the test. Owing to bad state of preservation no ornament 

 can be seen, the surface being worn smooth in all specimens found; 

 there is evidence of the presence of an umbo at the center of the test, 

 though not so marked as in typical specimens of O. ocalanus. Di- 

 ameter, up to 3.0 mm (broken) ; thickness, 0.5 mm. Sections show 

 12 to 14 chambers in the final whorl, chambers long and narrow and 

 the septa curved throughout, more strongly so as they approach the 

 periphery. As in typical 0. ocalanus the septa are somewhat raised 

 and there is a strong tendency toward thickening at the periphery. 



If we take into account the fact that all the specimens examined 

 were incomplete, the slight differences in size, number of whorls, and 

 number of chambers in the final whorl may be neglected, especially 

 as the proportional development is almost identical with typical 

 specimens of O. ocalanus from Ocala limestone. 



Pleswtyfes.—V.%:^M. nos. 497859 and 497860. 



Occurrence. — In Mexico the species occurs in the Tantoyuca for- 

 mation, which is considered to belong to the Jackson Eocene. A 

 larger species, very closely alHed to O. ocalanus., and for a long 

 time confused with that species, occurs in the Claiborne. This 

 has now been referred to a new species, Operculinoides jennyi. 



OPERCULINOIDES OCALANUS (Cnshman) MINOR, new variety 



Plate 12, Figure 4; Plate 15, Figubes 1, 2; Plate 21, Figubei 3 



A number of specimens of a small species of Operculinoides have 

 been sectioned and are referred to a variety of O. ocalanus (Cush- 

 man), though perhaps the differences from that species are sufficient 

 to warrant specific distinction. The test is much smaller but shows 

 a similar umbonate form, with raised septa, the septa showing 

 coarser beading or granulation than is customary in O. ocalanus. 



Sections show the test to consist of 21/2 whorls, with 15 or 16 

 chambers in the final whorl. The chambers are long and narrow, 

 the sutures gently and regularly curved, but showing in general a 

 rather more pronounced "angle" near the periphery than O. ocalanus., 

 as may be seen from the figures (pi. 15, figs. 1, 2). Diameter, 2.1 to 

 2.5 mm ; thickness, 0.4 mm. 



Cotypes.—V.^.'^.'M.. nos. 497861 and 497862. 



Occurrence. — This form occurs rarely in the Guayabal formation 

 (Tempoal of ver Wiebe and Muir, Claiborne) near the town of 

 Tantoyuca, Veracruz. The cotypes were obtained from a locality 

 east of Tempoal, Veracruz; collection of Dr. P. von Schumacher no. 

 2589. 



