22 PROCEEDINGS OF THE NATIONAL MUSEUM vol.67 



PAVONINA MEXICANA new species 



Plate 6, figs. 7-9 



Description. — Test large, about as long as broad, roughly triangular, 

 gradually tapering to the somewhat truncate base, much compressed; 

 chambers numerous, the earlier ones biserial, the later ones very 

 elongate, uniserial, apertural end rounded, sutures shghtly limbate, 

 sometimes beaded; wall slightly arenaceous, but smoothly finished; 

 apertures about the peripheral face. 



Length up to 1.25 mm. 



Type specimens.— (Cat. No. 353173 U.S.N.M,) from the Tertiary 

 of Mexico. This is in the Alazan Clay of Rio Buena Vista, 0.5 

 kms. 25° E. from Tumbadero Hacienda House, state of Vera Cruz, 

 T. W. Vaughan, collector. 



This is the only known locality for this species but it was in some 

 numbers at this place. In the early development there is a spiral 

 arrangement of the chambers before the alternating character is 

 taken on showing the relation of Spiroplecta and Textularia, as in 

 other genera of the Textulariidae. This coiling brings the pro- 

 loculum and early chambers some distance in from the periphery. 

 Often the proloculum is large, apparently megalospheric, and is 

 thicker than the rest of the test, giving an umbonate appearance to 

 the early portion. 



This Tertiary species is apparently the largest of the genus. 



PAVONINA ADVENA Cushman 



Pavonina advena Cushman, U. S. Geol. Survey Prof. Paper 133, 1923, p. 24, 

 pi. 1, fig. 10. 



Test of comparatively few chambers, only the very early ones 

 showing a trace of the biserial arrangement; succeeding chambers 

 rapidly increasing in width until an annular chamber is developed; 

 wall thin, translucent, finely punctate, otherwise smooth. 



Diameter slightly less than 0.50 mm. 



This somewhat resembles P. flahelliformis , which is characteristic 

 of certain parts of the Indo-Pacific region in shallow water but 

 which has much coarser pores. It is less closely like P. atlantica, 

 which I have described from material obtained off the Florida coast. 



The types were from U. S. G. S. station 7376, from Byram marl, 

 Lower Oligocene, Leaf River, Miss. 



There are two other species described from the Tertiary of Europe, 

 Pavonina agglutinans Schubert and P. lihurnica Stache, but I have 

 been unable to obtain specimens of these. 



PavoniTM lihurnica Stache ^^ does not from the figures seem to be a 

 species of this genus, and it is difficult to place it without seeing type 

 material. 



2»A bhandl.k.k. geol. Reichs., vol. 13, 1889, p. 89, pi. 6o. figs. 1 -19. 



