SPECIES OF CAMERINIDAE — BARKER 325 



The principal difference from typical C. jachsonensis lies in th© 

 more globose form of the test, as is indicated by the varietal name. 

 This is clearly shown by the transverse sections figured. 



Cotypes.—U.^.'^M. nos. 497891, 497894-497896. 



Other speciTnens.—V.S.^M. nos. 497892 and 497893. 



Occurrence. — The variety occurs in the Tantoyuca formation, 

 Jackson Eocene, possessing a similar range and distribution to the 

 typical form. 



CAMERINA GUAYABALENSIS, new species 



Plate 13, Figuee 4 ; Plate 18, Figuke 4 ; Plate 22, Figltke 3 



Test small to medium in size, compressed globose-lenticular, and 

 completely involute. The strongly developed rounded keel of clear 

 shell material gives a somewhat truncated appearance to the periph- 

 ery. Septa nearly straight, anastomosing to a variable extent at the 

 poles of the test, where there may be developed a small mass of clear 

 shell material. Diameter averages 2.8 mm, with a maximum ob- 

 served of 3.5 mm ; average thickness, 0.85 to 0.95 mm. 



Median sections show regular coiling with a thick outer wall 

 (forming the keel mentioned above). The chambers are typically 

 camerinid in character, being nearly as wide as long, with nearly 

 straight septa, slightly oblique and joining the periphery in a gentle 

 curve. There are 4% to 5 whorls, with 24 to 27 chambers in the 

 final whorl. The canal system is typically that of Camerina. 



This species is in many respects similar to G. vanderstoki (Rutten 

 and Vermunt), both in exterior and in section, but the latter is gen- 

 erally larger and thicker, does not show such a heavily developed 

 keel (with truncation of the periphery), and in section shows more 

 chambers in the final whorl (28 to 30 chambers in G. vanderstohi 

 compared with 24 to 27 in G. guaydbalensis) . 



Gotypes.—V.^.'^M. nos. 497897 and 497898. 



Occurrence. — In the Guayabal (Tempoal of ver Wiebe and Muir) 

 this species is of fairly frequent occurrence, in association as a rule 

 with Eulinderina guaydbalensis (Nuttall) and Operculinoides pre- 

 numrriulitiformis. Cotypes have been selected from Mecatepec Well 

 no. 5 and Poza Rica Well no. 8, Veracruz, the latter material giving 

 superior results on sectioning. 



CAMERINA PELLATISPIROIDES, new species 

 Plate 20, Figure 10 ; Plate 22, Figure 4 



While investigating samples from El Cristo Well no. 1 with a 

 view to obtaining topotype material of Discocyclina eristensis 

 (Vaughan) and Actinosiphon semmesi Vaughan, I found several 

 specimens of a small globose camerinid. On sectioning, the species 



